Anyone can get sick anytime, but some are more at risk than others. We are all regularly exposed to germs, and often, the immune system fights off infections before we feel them.
You may get sick more frequently because of a chronic health condition orcompromised immune system. Other factors, such as dehydration, diet, and environment, can also raise the risk of getting sick.
While it isn’t possible to prevent every illness, there are steps that you can take tosupport your immune healthand lower the risk of infection.
Roos Koole / Getty Images
1. Environment
Air pollutionis harmful to immune health.Exposure to pollutants may weaken your immune system over time. This is especially true for people who experienced high levels of air pollution at a young age while their bodies were still growing and developing. Air pollution also impacts heart health and may lead toasthma(disease causing narrowing and swelling of the airways).
The season can affect your risk of infection, as well. If you live in a cold-weather environment, you may be exposed to more viruses more frequently. This is because viruses spread more easily when people are spending more time indoors.
2. Diet
A person’s diet can impact their immune health and risk of getting sick. If your body does not receive certain nutrients, it cannot fight germs effectively.A diet focusing on whole and plant-based foods can help you stay healthy.
In addition, people with lowvitamin D levelsare at higher risk of developing acute respiratory tract infections like theflu,common cold, andCOVID-19.To increase your vitamin D levels, spend 10 to 15 minutes per day outside in the sun. Take avitamin D supplementor add vitamin D-rich foods to your diet. These foods include:
There are also other supplements that promise to helpboost the immune system.
People who regularly drink alcohol may get sick more often than those who drink in moderation or not at all. Heavy or frequent drinking may impact your immune health.
3. Dehydration
The body becomes dehydrated when it loses more water than it takes in.Chronic dehydrationmay increase the risk of infection. Every tissue and cell in the body needs water to function well. Dehydration affects kidney health and may raise the risk ofurinary tract infections(UTIs) andkidney disease.
4. Sleep Deprivation
People whodon’t get enough sleepare more likely to get sick.A lack of sleep lowers the body’s ability to fight infection. Research shows that adults who sleep for six hours or less each night are at increased risk of viral infections. They may also not receive as much immunity from vaccines as those who sleep at least seven hours per night.
Long-term sleep deprivation raises the risk of serious health problems, including heart disease anddiabetes. People who do not get enough sleep may also have shorter lifespans. Most adults need at least seven hours of sleep per night, children ages 6 to 12 need nine to 12 hours, and teens need eight to 10 hours every night.
10 Benefits of Sleep
5. Stress and Anxiety
Chronicstressandanxietyaffect immune health and lower the body’s ability to fight infection. Stress refers to the body’s ability to respond to demands and challenges.When the body is under stress, it releases the hormonecortisolinto the bloodstream. This is helpful for short-term stress, but if you have chronically high cortisol levels, your body experiences increased inflammation, which can lower its ability to fight infection.
Anxiety is a mental health condition that causes a state of excessive worry or panic.Anxiety causes several physical symptoms, including fatigue, muscle tension, sweating, and shortness of breath. It may also affect immune health and lead to heart disease over time.
Proven strategies to reduce stress and anxiety include:
6. Hand Hygiene
Regularhandwashingis a proven way to prevent infection. Touching shared surfaces such as doorknobs or light switches may expose a person to viruses or bacteria. Washing your hands reduces the risk of germs entering your body and causing illness.
To kill the germs on your hands, wash them under warm, running water with soap for 20 seconds. Hand sanitizer with at least 60% alcohol is also effective. Be sure to wash your hands before and after eating or preparing food. Handwashing is especially important when spending time with someone who is sick.
7. Lack of Physical Activity
Some lifestyle factors may affect your immune system’s ability to function well and fight infection. People who do not engage in regular physical activity may get sick more often than those who do. That is because physical activity increases your immunity. Whileexercisebenefits your health, extreme exercise, like running a marathon, may make you more susceptible to illness.
Obesitymay lower your body’s ability to fight infection. People who are obese are more likely to get sick and become more seriously ill than those with a healthy weight.Talk with a healthcare provider if you are at risk of obesity to develop a treatment plan.
8. Genetics
Your geneticscan affect how well your immune system functions.Genetics refers to the genes passed down to you from your parents.
Your risk may be higher if you have a family history of frequent infections or an autoimmune condition.
9. Immune System Disorders
Immune system disorders are chronic health conditions that affect the immune system’s function. People withautoimmune disordershave immune systems that attack healthy cells.Your immune system overreacts to certain substances if you have allergies or asthma. People with asthma are at higher risk of respiratory viruses.
There are also immune deficiency disorders, such as chronic granulomatous disease (CGD) and chronic neutropenia syndromes, that cause the immune system to not function properly. People with immune deficiency disorders are more likely to get sick and become ill when exposed to germs.
10. Loneliness
Having social interactions is linked to better health and is important for overall well-being. One study found that loneliness or isolation may worsen cold symptoms and take people longer to recover from an illness.
Loneliness and social isolation may also shorten your lifespan, worsen mental illness, increase the risk of Alzheimer’s disease and dementia, and impair the immune system.
Immunity naturally declines with age. The older we get, the more susceptible we are to infection.
A Word From Verywell
—ANJU GOEL, MD, MEDICAL EXPERT BOARD
Ways to Strengthen Immune Health
Fortunately, there are steps you can take to strengthen your immune health and lower your risk of infection.Consider the following strategies and lifestyle changes to boost your immunity:
13 Ways to Avoid Getting Sick When Your Family Is Ill
How Often Is Too Often?
For most people, getting sick from time to time is part of life. The average healthy adult in the United States experiences about two to three colds yearly. Atypical cold lasts for about one weekbut may be longer. Children experience more colds than adults.
See a healthcare provider if you are getting sick more frequently or have colds lasting longer than one week. See your provider if your symptoms are severe or you have a high fever for more than four days. Seek immediate medical attention if you develop trouble breathing.
Summary
Getting sick is often uncomfortable and inconvenient. Many people seek ways to stay healthy, especially in the winter months. To help your immune system function optimally, take steps to support your health and lower your exposure to germs.
Eat a balanced diet of nutritious foods and exercise daily. Manage your stress levels and aim to get seven to eight hours of sleep each night. Keep your body hydrated daily, focus on good dental care, and wash your hands frequently.
34 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Glencross DA, Ho TR, Camiña N, et al.Air pollution and its effects on the immune system.Free Radic Biol Med. 2020;151:56-68. doi:10.1016/j.freeradbiomed.2020.01.179Prunicki M, Cauwenberghs N, Lee J, et al.Air pollution exposure is linked with methylation of immunoregulatory genes, altered immune cell profiles, and increased blood pressure in children.Sci Rep. 2021;11(1):4067. doi:10.1038/s41598-021-83577-3National Institute of Health. News in Health.Is it flu, COVID-19, allergies, or a cold?Harvard T.H. Chan. School of Public Health.Nutrition and immunity.Ao T, Kikuta J, Ishii M.The effects of vitamin D on immune system and inflammatory diseases.Biomolecules. 2021;11(11):1624. doi:10.3390/biom11111624Barr T, Helms C, Grant K, et al.Opposing effects of alcohol on the immune system.Prog Neuropsychopharmacol Biol Psychiatry. 2016;65:242-251. doi:10.1016/j.pnpbp.2015.09.001Johnson RJ, Sánchez-Lozada LG, Newman LS, et al.Climate change and the kidney.Ann Nutr Metab. 2019;74 Suppl 3:38-44. doi:10.1159/000500344Haspel JA, Anafi R, Brown MK, et al.Perfect timing: circadian rhythms, sleep, and immunity - an NIH workshop summary.JCI Insight. 2020;5(1):e131487. doi:10.1172/jci.insight.131487National Institute of Health.How much sleep do I need?MedlinePlus.Stress.Zefferino R, Di Gioia S, Conese M.Molecular links between endocrine, nervous and immune system during chronic stress.Brain Behav. 2021;11(2):e01960. doi:10.1002/brb3.1960Goyal M, Singh S, Sibinga EM, et al.Meditation programs for psychological stress and well-being: a systematic review and meta-analysis.JAMA Intern Med. 2014;174(3):357-368. doi:10.1001/jamainternmed.2013.13018National Institute of Mental Health.Any anxiety disorder.National Institute of Mental Health.Anxiety disorders.National Institute of Mental Health.I’m so stressed out! fact sheet.Centers for Disease Control and Prevention.About handwashing.MedlinePlus.Exercise and immunity.de Frel DL, Atsma DE, Pijl H, et al.The impact of obesity and lifestyle on the immune system and susceptibility to infections such as COVID-19.Front Nutr. 2020;7:597600. doi:10.3389/fnut.2020.597600Chen J, Yang P, Zhang Q, et al.Genetic risk of clozapine-induced leukopenia and neutropenia: a genome-wide association study.Transl Psychiatry. 2021;11(1):343. doi:10.1038/s41398-021-01470-zDe Arras L, Laws R, Leach SM, et al.Comparative genomics RNAi screen identifies Eftud2 as a novel regulator of innate immunity.Genetics. 2014;197(2):485-496. doi:10.1534/genetics.113.160499MedlinePlus.Autoimmune diseases.MedlinePlus.Immune system and disorders.National Institute of Allergy and Infectious Diseases.Types of primary immune deficiency diseases.LeRoy AS, Murdock KW, Jaremka LM, Loya A, Fagundes CP.Loneliness predicts self-reported cold symptoms after a viral challenge.Health Psychol. 2017 May;36(5):512-520. doi:10.1037/hea0000467HelpGuide.org.Loneliness and isolation.Weyand CM, Goronzy JJ.Aging of the immune system. Mechanisms and therapeutic targets.Ann Am Thorac Soc. 2016;13 Suppl 5(Suppl 5):S422-S428. doi:10.1513/AnnalsATS.201602-095AWCenters for Disease Control and Prevention.Healthy habits: enhancing immunity.Harvard Health Publishing.How to boost your immune system.Sobolewska-Włodarczyk A, Włodarczyk M, Talar M, et al.The association of the quality of sleep with proinflammatory cytokine profile in inflammatory bowel disease patients.Pharmacol Rep. 2021;73(6):1660-1669. doi:10.1007/s43440-021-00333-0National Institute on Alcohol Abuse and Alcoholism.Drinking levels defined.Gutiérrez S, Svahn SL, Johansson ME.Effects of omega-3 fatty acids on immune cells.Int J Mol Sci. 2019;20(20):5028. doi:10.3390/ijms20205028MedlinePlus.Exercise and immunity.MedlinePlus.Learn to manage stress.American Lung Association.Facts about the common cold.
34 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Glencross DA, Ho TR, Camiña N, et al.Air pollution and its effects on the immune system.Free Radic Biol Med. 2020;151:56-68. doi:10.1016/j.freeradbiomed.2020.01.179Prunicki M, Cauwenberghs N, Lee J, et al.Air pollution exposure is linked with methylation of immunoregulatory genes, altered immune cell profiles, and increased blood pressure in children.Sci Rep. 2021;11(1):4067. doi:10.1038/s41598-021-83577-3National Institute of Health. News in Health.Is it flu, COVID-19, allergies, or a cold?Harvard T.H. Chan. School of Public Health.Nutrition and immunity.Ao T, Kikuta J, Ishii M.The effects of vitamin D on immune system and inflammatory diseases.Biomolecules. 2021;11(11):1624. doi:10.3390/biom11111624Barr T, Helms C, Grant K, et al.Opposing effects of alcohol on the immune system.Prog Neuropsychopharmacol Biol Psychiatry. 2016;65:242-251. doi:10.1016/j.pnpbp.2015.09.001Johnson RJ, Sánchez-Lozada LG, Newman LS, et al.Climate change and the kidney.Ann Nutr Metab. 2019;74 Suppl 3:38-44. doi:10.1159/000500344Haspel JA, Anafi R, Brown MK, et al.Perfect timing: circadian rhythms, sleep, and immunity - an NIH workshop summary.JCI Insight. 2020;5(1):e131487. doi:10.1172/jci.insight.131487National Institute of Health.How much sleep do I need?MedlinePlus.Stress.Zefferino R, Di Gioia S, Conese M.Molecular links between endocrine, nervous and immune system during chronic stress.Brain Behav. 2021;11(2):e01960. doi:10.1002/brb3.1960Goyal M, Singh S, Sibinga EM, et al.Meditation programs for psychological stress and well-being: a systematic review and meta-analysis.JAMA Intern Med. 2014;174(3):357-368. doi:10.1001/jamainternmed.2013.13018National Institute of Mental Health.Any anxiety disorder.National Institute of Mental Health.Anxiety disorders.National Institute of Mental Health.I’m so stressed out! fact sheet.Centers for Disease Control and Prevention.About handwashing.MedlinePlus.Exercise and immunity.de Frel DL, Atsma DE, Pijl H, et al.The impact of obesity and lifestyle on the immune system and susceptibility to infections such as COVID-19.Front Nutr. 2020;7:597600. doi:10.3389/fnut.2020.597600Chen J, Yang P, Zhang Q, et al.Genetic risk of clozapine-induced leukopenia and neutropenia: a genome-wide association study.Transl Psychiatry. 2021;11(1):343. doi:10.1038/s41398-021-01470-zDe Arras L, Laws R, Leach SM, et al.Comparative genomics RNAi screen identifies Eftud2 as a novel regulator of innate immunity.Genetics. 2014;197(2):485-496. doi:10.1534/genetics.113.160499MedlinePlus.Autoimmune diseases.MedlinePlus.Immune system and disorders.National Institute of Allergy and Infectious Diseases.Types of primary immune deficiency diseases.LeRoy AS, Murdock KW, Jaremka LM, Loya A, Fagundes CP.Loneliness predicts self-reported cold symptoms after a viral challenge.Health Psychol. 2017 May;36(5):512-520. doi:10.1037/hea0000467HelpGuide.org.Loneliness and isolation.Weyand CM, Goronzy JJ.Aging of the immune system. Mechanisms and therapeutic targets.Ann Am Thorac Soc. 2016;13 Suppl 5(Suppl 5):S422-S428. doi:10.1513/AnnalsATS.201602-095AWCenters for Disease Control and Prevention.Healthy habits: enhancing immunity.Harvard Health Publishing.How to boost your immune system.Sobolewska-Włodarczyk A, Włodarczyk M, Talar M, et al.The association of the quality of sleep with proinflammatory cytokine profile in inflammatory bowel disease patients.Pharmacol Rep. 2021;73(6):1660-1669. doi:10.1007/s43440-021-00333-0National Institute on Alcohol Abuse and Alcoholism.Drinking levels defined.Gutiérrez S, Svahn SL, Johansson ME.Effects of omega-3 fatty acids on immune cells.Int J Mol Sci. 2019;20(20):5028. doi:10.3390/ijms20205028MedlinePlus.Exercise and immunity.MedlinePlus.Learn to manage stress.American Lung Association.Facts about the common cold.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Glencross DA, Ho TR, Camiña N, et al.Air pollution and its effects on the immune system.Free Radic Biol Med. 2020;151:56-68. doi:10.1016/j.freeradbiomed.2020.01.179Prunicki M, Cauwenberghs N, Lee J, et al.Air pollution exposure is linked with methylation of immunoregulatory genes, altered immune cell profiles, and increased blood pressure in children.Sci Rep. 2021;11(1):4067. doi:10.1038/s41598-021-83577-3National Institute of Health. News in Health.Is it flu, COVID-19, allergies, or a cold?Harvard T.H. Chan. School of Public Health.Nutrition and immunity.Ao T, Kikuta J, Ishii M.The effects of vitamin D on immune system and inflammatory diseases.Biomolecules. 2021;11(11):1624. doi:10.3390/biom11111624Barr T, Helms C, Grant K, et al.Opposing effects of alcohol on the immune system.Prog Neuropsychopharmacol Biol Psychiatry. 2016;65:242-251. doi:10.1016/j.pnpbp.2015.09.001Johnson RJ, Sánchez-Lozada LG, Newman LS, et al.Climate change and the kidney.Ann Nutr Metab. 2019;74 Suppl 3:38-44. doi:10.1159/000500344Haspel JA, Anafi R, Brown MK, et al.Perfect timing: circadian rhythms, sleep, and immunity - an NIH workshop summary.JCI Insight. 2020;5(1):e131487. doi:10.1172/jci.insight.131487National Institute of Health.How much sleep do I need?MedlinePlus.Stress.Zefferino R, Di Gioia S, Conese M.Molecular links between endocrine, nervous and immune system during chronic stress.Brain Behav. 2021;11(2):e01960. doi:10.1002/brb3.1960Goyal M, Singh S, Sibinga EM, et al.Meditation programs for psychological stress and well-being: a systematic review and meta-analysis.JAMA Intern Med. 2014;174(3):357-368. doi:10.1001/jamainternmed.2013.13018National Institute of Mental Health.Any anxiety disorder.National Institute of Mental Health.Anxiety disorders.National Institute of Mental Health.I’m so stressed out! fact sheet.Centers for Disease Control and Prevention.About handwashing.MedlinePlus.Exercise and immunity.de Frel DL, Atsma DE, Pijl H, et al.The impact of obesity and lifestyle on the immune system and susceptibility to infections such as COVID-19.Front Nutr. 2020;7:597600. doi:10.3389/fnut.2020.597600Chen J, Yang P, Zhang Q, et al.Genetic risk of clozapine-induced leukopenia and neutropenia: a genome-wide association study.Transl Psychiatry. 2021;11(1):343. doi:10.1038/s41398-021-01470-zDe Arras L, Laws R, Leach SM, et al.Comparative genomics RNAi screen identifies Eftud2 as a novel regulator of innate immunity.Genetics. 2014;197(2):485-496. doi:10.1534/genetics.113.160499MedlinePlus.Autoimmune diseases.MedlinePlus.Immune system and disorders.National Institute of Allergy and Infectious Diseases.Types of primary immune deficiency diseases.LeRoy AS, Murdock KW, Jaremka LM, Loya A, Fagundes CP.Loneliness predicts self-reported cold symptoms after a viral challenge.Health Psychol. 2017 May;36(5):512-520. doi:10.1037/hea0000467HelpGuide.org.Loneliness and isolation.Weyand CM, Goronzy JJ.Aging of the immune system. Mechanisms and therapeutic targets.Ann Am Thorac Soc. 2016;13 Suppl 5(Suppl 5):S422-S428. doi:10.1513/AnnalsATS.201602-095AWCenters for Disease Control and Prevention.Healthy habits: enhancing immunity.Harvard Health Publishing.How to boost your immune system.Sobolewska-Włodarczyk A, Włodarczyk M, Talar M, et al.The association of the quality of sleep with proinflammatory cytokine profile in inflammatory bowel disease patients.Pharmacol Rep. 2021;73(6):1660-1669. doi:10.1007/s43440-021-00333-0National Institute on Alcohol Abuse and Alcoholism.Drinking levels defined.Gutiérrez S, Svahn SL, Johansson ME.Effects of omega-3 fatty acids on immune cells.Int J Mol Sci. 2019;20(20):5028. doi:10.3390/ijms20205028MedlinePlus.Exercise and immunity.MedlinePlus.Learn to manage stress.American Lung Association.Facts about the common cold.
Glencross DA, Ho TR, Camiña N, et al.Air pollution and its effects on the immune system.Free Radic Biol Med. 2020;151:56-68. doi:10.1016/j.freeradbiomed.2020.01.179
Prunicki M, Cauwenberghs N, Lee J, et al.Air pollution exposure is linked with methylation of immunoregulatory genes, altered immune cell profiles, and increased blood pressure in children.Sci Rep. 2021;11(1):4067. doi:10.1038/s41598-021-83577-3
National Institute of Health. News in Health.Is it flu, COVID-19, allergies, or a cold?
Harvard T.H. Chan. School of Public Health.Nutrition and immunity.
Ao T, Kikuta J, Ishii M.The effects of vitamin D on immune system and inflammatory diseases.Biomolecules. 2021;11(11):1624. doi:10.3390/biom11111624
Barr T, Helms C, Grant K, et al.Opposing effects of alcohol on the immune system.Prog Neuropsychopharmacol Biol Psychiatry. 2016;65:242-251. doi:10.1016/j.pnpbp.2015.09.001
Johnson RJ, Sánchez-Lozada LG, Newman LS, et al.Climate change and the kidney.Ann Nutr Metab. 2019;74 Suppl 3:38-44. doi:10.1159/000500344
Haspel JA, Anafi R, Brown MK, et al.Perfect timing: circadian rhythms, sleep, and immunity - an NIH workshop summary.JCI Insight. 2020;5(1):e131487. doi:10.1172/jci.insight.131487
National Institute of Health.How much sleep do I need?
MedlinePlus.Stress.
Zefferino R, Di Gioia S, Conese M.Molecular links between endocrine, nervous and immune system during chronic stress.Brain Behav. 2021;11(2):e01960. doi:10.1002/brb3.1960
Goyal M, Singh S, Sibinga EM, et al.Meditation programs for psychological stress and well-being: a systematic review and meta-analysis.JAMA Intern Med. 2014;174(3):357-368. doi:10.1001/jamainternmed.2013.13018
National Institute of Mental Health.Any anxiety disorder.
National Institute of Mental Health.Anxiety disorders.
National Institute of Mental Health.I’m so stressed out! fact sheet.
Centers for Disease Control and Prevention.About handwashing.
MedlinePlus.Exercise and immunity.
de Frel DL, Atsma DE, Pijl H, et al.The impact of obesity and lifestyle on the immune system and susceptibility to infections such as COVID-19.Front Nutr. 2020;7:597600. doi:10.3389/fnut.2020.597600
Chen J, Yang P, Zhang Q, et al.Genetic risk of clozapine-induced leukopenia and neutropenia: a genome-wide association study.Transl Psychiatry. 2021;11(1):343. doi:10.1038/s41398-021-01470-z
De Arras L, Laws R, Leach SM, et al.Comparative genomics RNAi screen identifies Eftud2 as a novel regulator of innate immunity.Genetics. 2014;197(2):485-496. doi:10.1534/genetics.113.160499
MedlinePlus.Autoimmune diseases.
MedlinePlus.Immune system and disorders.
National Institute of Allergy and Infectious Diseases.Types of primary immune deficiency diseases.
LeRoy AS, Murdock KW, Jaremka LM, Loya A, Fagundes CP.Loneliness predicts self-reported cold symptoms after a viral challenge.Health Psychol. 2017 May;36(5):512-520. doi:10.1037/hea0000467
HelpGuide.org.Loneliness and isolation.
Weyand CM, Goronzy JJ.Aging of the immune system. Mechanisms and therapeutic targets.Ann Am Thorac Soc. 2016;13 Suppl 5(Suppl 5):S422-S428. doi:10.1513/AnnalsATS.201602-095AW
Centers for Disease Control and Prevention.Healthy habits: enhancing immunity.
Harvard Health Publishing.How to boost your immune system.
Sobolewska-Włodarczyk A, Włodarczyk M, Talar M, et al.The association of the quality of sleep with proinflammatory cytokine profile in inflammatory bowel disease patients.Pharmacol Rep. 2021;73(6):1660-1669. doi:10.1007/s43440-021-00333-0
National Institute on Alcohol Abuse and Alcoholism.Drinking levels defined.
Gutiérrez S, Svahn SL, Johansson ME.Effects of omega-3 fatty acids on immune cells.Int J Mol Sci. 2019;20(20):5028. doi:10.3390/ijms20205028
MedlinePlus.Learn to manage stress.
American Lung Association.Facts about the common cold.
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