Table of ContentsView AllTable of ContentsAnatomyFunctionConditionsAgingSubcutaneous InjectionsFAQ
Table of ContentsView All
View All
Table of Contents
Anatomy
Function
Conditions
Aging
Subcutaneous Injections
FAQ
The hypodermis is the bottomlayerof skin. Also known assubcutaneous tissue, the hypodermis insulates and protects the body, stores energy (in the form of fat), helps to regulate body temperature, and connects the skin to muscles and bones.
The hypodermis is one of the three layers of human skin, the others being theepidermis(outer layer) anddermis(middle layer). Together, these layers provide abarrier against fluids, infection, and trauma.
This article discusses the hypodermis layer of the skin. It explains the anatomy and function of the subcutaneous tissue. It also covers potential health conditions and the effect of aging on the hypodermis.
Anatomy of the Hypodermis
The hypodermis is the innermost or subcutaneous layer of theskin. Most of the body’s fat is stored in this layer. It provides insulation, protection, temperature regulation, and connection between the bones and muscles.
Location
The hypodermis is the innermost layer of the skin located under the dermis (outer layer) and the epidermis (middle layer). The thickness of the hypodermis varies in different regions of the body and can vary considerably between different people.
The hypodermis layer also provides shaping and contouring. For those assigned male at birth, the hypodermis is thickest in the abdomen and shoulders. Whereas the hypodermis for those assigned female at birth is generally thickest in the hips, thighs, and buttocks.
Structure
The hypodermis is a complex structure composed of different cells, tissues, glands, and vessels that work together to protect the body and ensure that it functions normally.
The components of the hypodermis include:
Function of the Hypodermis
The hypodermis serves several vital functions in the human body. These include:
Connective tissues in the hypodermis also support structures such as nerves and blood vessels.
Functions of Connective Tissue
Associated Conditions
The following are medical disorders and procedures related to this unique layer of the skin.
Hypothermia and Overheating
The hypodermis is essential for body temperature regulation. It traps heat and protects you from the cold.
With age, the hypodermis thins. This is one of the reasons that older people are more prone tohypothermia.
Obesity
Body fat in the hypodermis layer is called subcutaneous adipose tissue (SAT). This is different thanvisceraladipose tissue (VAT) that lines internal organs. Excess fat in either area leads to obesity.
Both types of fat have received a lot of attention in recent years due to thegrowing rate of obesity.Studies note that not all body fat is equal, at least with respect to its role inmetabolic syndromeand heart disease.
Bedsores
Bedsores, otherwise known as pressure ulcers, occur when sustained pressure on the skin causes open sores that can extend deep into the hypodermis. Bedsores are most common in people who are bedbound or consistently use a wheelchair.
Bedsores are difficult to treat and can lead to complications if not treated aggressively. This includes bone infection,autonomic dysreflexia(overactive involuntary nerves), andsepsis(a potentially life-threatening response to a whole-body infection).
Panniculitis
Panniculitisrefers to inflammation of subcutaneous fat. It is an uncommon condition that causes hardened nodules or plaques that you can feel and sometimes see.
Panniculitis commonly affects the shins and calves before spreading to the thighs and upper body. It usually clears within six weeks, leaving no scars. Swelling, redness, bruising, and joint pain are common.
The causes of panniculitis are many and include:
Third-Degree Burns
Third-degree burnsare those that destroy the epidermis and dermis and expose the hypodermis. This can lead to the potentially life-threatening loss of fluid and heat, depending on how extensive the burn is. It also increases the risk of severe bacterial infection and permanent nerve damage.
Third-degree burns can appear dry and leathery with a combination of red, white, or blackened tissues. You may also see the yellowish adipose tissues peeking through. Because many nerve endings will have been destroyed, third-degree burns aren’t usually painful to the touch.
Skin Cancer
Skin cancers(includingmelanoma,squamous cell carcinoma, andbasal cell carcinoma) typically start in the epidermis where sun exposure is greatest but can migrate to the underlying dermis and hypodermis.
One exception issoft tissue sarcomaswhich originate in the body’s soft tissues. These include tissues like muscle, fat, blood vessels, nerves, tendons, and cartilage. Soft tissue sarcoma can happen anywhere in the body but most often involves the arms, legs, and abdomen.
The Hypodermis and Aging
While the hypodermis is not visible, it can dramatically affect the appearance of the skin. This is due to the way aging impacts the skin, specifically in the area of the face and neck.
With aging, the volume of facial fat decreases, and there is less supportive tissue to support the normalturgoror elasticity of the skin.
As a result, the facial skin begins to droop and sag, resulting in a look that can be interpreted as appearing tired. The bones and muscles of the face also lose volume.
Skin Elasticity: What It Is and How to Protect It
The Hypodermis and Injections
Medications can be injected into different areas of the body, such as into a vein (intravenous injections), into a muscle (intramuscular injections), into the dermis (intradermal injections), or into fatty tissue (subcutaneous injections).
Some medications can only be given through one route, while others can be given through multiple routes. It depends on the type and goal of the medication and how it’s best absorbed in the body.
Summary
The hypodermis is the innermost layer of the skin. It stores fat and energy, pads and protects the body, attaches skin to the bones and muscles, and is very important in maintaining body temperature. This layer can be used for injections with some types of medication.
The hypodermis provides shaping and contour. The thickness varies per person, with excess fat in this layer leading to obesity. This layer of the skin thins with age, increasing the risk of hypothermia or heat exhaustion.
Frequently Asked Questions
The hypodermis fulfills several important functions:
Learn MoreWhat Is Normal Body Temperature?
The hypodermis contains fibroblasts (a type of cell commonly found in connective tissues), adipose tissues (fat cells), macrophages (a type of white blood cell that protects the body from harmful bacteria), and connective tissues that hold blood vessels and nerves.
There are three layers of the skin, including the epidermis, dermis, and hypodermis. The dermis is below the epidermal layer of skin that you see and above the hypodermis. Between them, it works to produce sweat and oil, grow hair, and provide sensitivity and structure to the skin.Learn MoreWhat Is the Dermis?
There are three layers of the skin, including the epidermis, dermis, and hypodermis. The dermis is below the epidermal layer of skin that you see and above the hypodermis. Between them, it works to produce sweat and oil, grow hair, and provide sensitivity and structure to the skin.
Learn MoreWhat Is the Dermis?
14 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.Stecco C, Hammer W, Vleeming A, Caro RD.Subcutaneous tissue and superficial fascia.Functional Atlas of the Human Fascial System. 2015:21-49. doi:10.1016/b978-0-7020-4430-4.00002-6Abdo J, Sopko N, Milner S.The applied anatomy of human skin: a model for regeneration.Wound Medicine. 2020;28:100179. doi:10.1016/j.wndm.2020.100179Cunha MGD, Rezende FC, Cunha ALGD, Machado CA, Fonseca FLA.Anatomical, histological and metabolic differences between hypodermis and subcutaneous adipose tissue.International Archives of Medicine. 2017;10. doi:10.3823/2422Shpichka A, Butnaru D, Bezrukov E, et al.Skin tissue regeneration for burn injury.Stem Cell Res Ther. 2019;10(1):94. doi:10.1186/s13287-019-1203-3Saxon SV, Etten MJ, Perkins EA.Physical change & aging: a guide for the helping professions. chapter 3: The skin, hair, and nails.New York: Springer Pub. Co.; 2014.Mittal B.Subcutaneous adipose tissue & visceral adipose tissue.Indian J Med Res. 2019;149(5):571-573. doi:10.4103/ijmr.IJMR_1910_18MedlinePlus.How to care for pressure sores.Wick MR.Panniculitis: a summary.Semin Diagn Pathol. 2017;34(3):261-72. doi:10.1053/j.semdp.2016.12.004Knowlin L, Stanford L, Moore D, Cairns B, Charles A.The measured effect magnitude of co-morbidities on burn injury mortality.Burns J Int Soc Burn Injur.2016;42(7):1433–8. doi:10.1016/j.burns.2016.03.007Skin Cancer Foundation.Skin cancer 101.Hoefkens F, Dehandschutter C, Somville J, Meijnders P, Van Gestel D.Soft tissue sarcoma of the extremities: pending questions on surgery and radiotherapy.Radiat Oncol. 2016;11(1):136. doi:10.1186/s13014-016-0668-9National Library of Medicine (NIH).Subcutaneous (SQ) injections.Stanford Children’s Health.Anatomy of the skin.National Human Genome Research Institute.Fibroblast.Additional ReadingKumar V, Abul AK, Aster JC, Perkins JA.Robbins and Cotran Pathologic Basis of Disease.Philadelphia, PA: Elsevier/Saunders, 2015. Print.
14 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.Stecco C, Hammer W, Vleeming A, Caro RD.Subcutaneous tissue and superficial fascia.Functional Atlas of the Human Fascial System. 2015:21-49. doi:10.1016/b978-0-7020-4430-4.00002-6Abdo J, Sopko N, Milner S.The applied anatomy of human skin: a model for regeneration.Wound Medicine. 2020;28:100179. doi:10.1016/j.wndm.2020.100179Cunha MGD, Rezende FC, Cunha ALGD, Machado CA, Fonseca FLA.Anatomical, histological and metabolic differences between hypodermis and subcutaneous adipose tissue.International Archives of Medicine. 2017;10. doi:10.3823/2422Shpichka A, Butnaru D, Bezrukov E, et al.Skin tissue regeneration for burn injury.Stem Cell Res Ther. 2019;10(1):94. doi:10.1186/s13287-019-1203-3Saxon SV, Etten MJ, Perkins EA.Physical change & aging: a guide for the helping professions. chapter 3: The skin, hair, and nails.New York: Springer Pub. Co.; 2014.Mittal B.Subcutaneous adipose tissue & visceral adipose tissue.Indian J Med Res. 2019;149(5):571-573. doi:10.4103/ijmr.IJMR_1910_18MedlinePlus.How to care for pressure sores.Wick MR.Panniculitis: a summary.Semin Diagn Pathol. 2017;34(3):261-72. doi:10.1053/j.semdp.2016.12.004Knowlin L, Stanford L, Moore D, Cairns B, Charles A.The measured effect magnitude of co-morbidities on burn injury mortality.Burns J Int Soc Burn Injur.2016;42(7):1433–8. doi:10.1016/j.burns.2016.03.007Skin Cancer Foundation.Skin cancer 101.Hoefkens F, Dehandschutter C, Somville J, Meijnders P, Van Gestel D.Soft tissue sarcoma of the extremities: pending questions on surgery and radiotherapy.Radiat Oncol. 2016;11(1):136. doi:10.1186/s13014-016-0668-9National Library of Medicine (NIH).Subcutaneous (SQ) injections.Stanford Children’s Health.Anatomy of the skin.National Human Genome Research Institute.Fibroblast.Additional ReadingKumar V, Abul AK, Aster JC, Perkins JA.Robbins and Cotran Pathologic Basis of Disease.Philadelphia, PA: Elsevier/Saunders, 2015. Print.
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.
Stecco C, Hammer W, Vleeming A, Caro RD.Subcutaneous tissue and superficial fascia.Functional Atlas of the Human Fascial System. 2015:21-49. doi:10.1016/b978-0-7020-4430-4.00002-6Abdo J, Sopko N, Milner S.The applied anatomy of human skin: a model for regeneration.Wound Medicine. 2020;28:100179. doi:10.1016/j.wndm.2020.100179Cunha MGD, Rezende FC, Cunha ALGD, Machado CA, Fonseca FLA.Anatomical, histological and metabolic differences between hypodermis and subcutaneous adipose tissue.International Archives of Medicine. 2017;10. doi:10.3823/2422Shpichka A, Butnaru D, Bezrukov E, et al.Skin tissue regeneration for burn injury.Stem Cell Res Ther. 2019;10(1):94. doi:10.1186/s13287-019-1203-3Saxon SV, Etten MJ, Perkins EA.Physical change & aging: a guide for the helping professions. chapter 3: The skin, hair, and nails.New York: Springer Pub. Co.; 2014.Mittal B.Subcutaneous adipose tissue & visceral adipose tissue.Indian J Med Res. 2019;149(5):571-573. doi:10.4103/ijmr.IJMR_1910_18MedlinePlus.How to care for pressure sores.Wick MR.Panniculitis: a summary.Semin Diagn Pathol. 2017;34(3):261-72. doi:10.1053/j.semdp.2016.12.004Knowlin L, Stanford L, Moore D, Cairns B, Charles A.The measured effect magnitude of co-morbidities on burn injury mortality.Burns J Int Soc Burn Injur.2016;42(7):1433–8. doi:10.1016/j.burns.2016.03.007Skin Cancer Foundation.Skin cancer 101.Hoefkens F, Dehandschutter C, Somville J, Meijnders P, Van Gestel D.Soft tissue sarcoma of the extremities: pending questions on surgery and radiotherapy.Radiat Oncol. 2016;11(1):136. doi:10.1186/s13014-016-0668-9National Library of Medicine (NIH).Subcutaneous (SQ) injections.Stanford Children’s Health.Anatomy of the skin.National Human Genome Research Institute.Fibroblast.
Stecco C, Hammer W, Vleeming A, Caro RD.Subcutaneous tissue and superficial fascia.Functional Atlas of the Human Fascial System. 2015:21-49. doi:10.1016/b978-0-7020-4430-4.00002-6
Abdo J, Sopko N, Milner S.The applied anatomy of human skin: a model for regeneration.Wound Medicine. 2020;28:100179. doi:10.1016/j.wndm.2020.100179
Cunha MGD, Rezende FC, Cunha ALGD, Machado CA, Fonseca FLA.Anatomical, histological and metabolic differences between hypodermis and subcutaneous adipose tissue.International Archives of Medicine. 2017;10. doi:10.3823/2422
Shpichka A, Butnaru D, Bezrukov E, et al.Skin tissue regeneration for burn injury.Stem Cell Res Ther. 2019;10(1):94. doi:10.1186/s13287-019-1203-3
Saxon SV, Etten MJ, Perkins EA.Physical change & aging: a guide for the helping professions. chapter 3: The skin, hair, and nails.New York: Springer Pub. Co.; 2014.
Mittal B.Subcutaneous adipose tissue & visceral adipose tissue.Indian J Med Res. 2019;149(5):571-573. doi:10.4103/ijmr.IJMR_1910_18
MedlinePlus.How to care for pressure sores.
Wick MR.Panniculitis: a summary.Semin Diagn Pathol. 2017;34(3):261-72. doi:10.1053/j.semdp.2016.12.004
Knowlin L, Stanford L, Moore D, Cairns B, Charles A.The measured effect magnitude of co-morbidities on burn injury mortality.Burns J Int Soc Burn Injur.2016;42(7):1433–8. doi:10.1016/j.burns.2016.03.007
Skin Cancer Foundation.Skin cancer 101.
Hoefkens F, Dehandschutter C, Somville J, Meijnders P, Van Gestel D.Soft tissue sarcoma of the extremities: pending questions on surgery and radiotherapy.Radiat Oncol. 2016;11(1):136. doi:10.1186/s13014-016-0668-9
National Library of Medicine (NIH).Subcutaneous (SQ) injections.
Stanford Children’s Health.Anatomy of the skin.
National Human Genome Research Institute.Fibroblast.
Kumar V, Abul AK, Aster JC, Perkins JA.Robbins and Cotran Pathologic Basis of Disease.Philadelphia, PA: Elsevier/Saunders, 2015. Print.
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