People often describe localized swollen areas on, or under, the skin as lumps or bumps. While bumps on, or under, the skin may result from conditions that give rise to a skin rash, many other conditions can result in solitary raised lumps on the skin. Infections, tumors, and the body's response to trauma or injury can all lead to lumps or bumps that appear to be located on or underneath the skin.
Depending upon the cause, skin lumps or bumps may vary in size and be firm or soft to the touch. The overlying skin may be reddened or ulcerated. Skin bumps may or may not be painful or tender, depending upon the cause of the lesions.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.
Causes of Bumps on Skin
Acne is a localized skin inflammation as a result of overactivity of oil glands at the base of hair follicles. This...
Actinic keratoses are rough, scaly patches of skin that are considered precancerous and are due to sun exposure. Prevention is to...
Anthrax is a deadly infectious disease that may be transmitted to humans by infected animals or by biological warfare. There are...
Eczema is a general term for many types dermatitis (skin inflammation). Atopic dermatitis is the most common of the many types of...
Bedbugs (from the insect family Cimicidae) are small, reddish-brown tick-like insects that feed by sucking the blood of mammals....
Birthmarks and other abnormal skin pigmentation is caused by the body's inability to produce enough melanin. Abnormal skin...
Boils (Skin Abscesses)
A boil is a skin abscess, a collection of pus localized deep in the skin. There are several different types of boils. Among them...
Bug Bites and Stings
Bug bites and stings have been known to transmit insect-borne illnesses such as West Nile virus, Rocky Mountain spotted fever,...
Cellulitis is an acute spreading bacterial infection below the surface of the skin characterized by redness, warmth,...
Chickenpox (chicken pox) is a contagious childhood disease caused by the varicella-zoster virus. Symptoms have an incubation...
Contact dermatitis is a rash that occurs after exposure to an irritant. It can be allergic. Symptoms include a red, elevated rash...
Corns and calluses are sometimes painful areas of thickened skin that appear between the toes and fingers or on the soles of the...
Cysts are sac-like structures that may be filled with gas, liquid, or solid materials. Cysts may produce symptoms and signs...
Erythema nodosum is a skin inflammation that results in reddish, painful, tender lumps most commonly located in the front of the...
Folliculitis is a skin condition that causes small red bumps to form around the hair follicles. Skin bacteria such as...
Gout (Gouty Arthritis)
Buildup of uric acid crystals in a joint causes gouty arthritis. Symptoms and signs include joint pain, swelling, heat, and...
Hidradenitis suppurativa (HS) is a chronic skin condition that causes painful red abscesses in the groin and armpits that may...
Hives (Urticaria & Angioedema)
Hives, also called urticaria, is a raised, itchy area of skin that is usually a sign of an allergic reaction. The allergy may be...
How Do I Get Rid of Intertrigo?
Intertrigo is painful and itchy skin inflammation that occurs between skin folds, such as in the groin, buttocks, or between fat...
Impetigo is a contagious skin infection caused by staph and strep bacteria. There are two types of impetigo: nonbullous and...
Ingrown hairs may be caused by improper shaving, waxing, or blockage of the hair follicle. Symptoms and signs of ingrown hairs...
Insect Sting Allergies
The majority of stinging insects in the United States are from bees, yellow jackets, hornets, wasps, and fire ants. Severity of...
Is Eczema Contagious?
Eczema is a skin condition characterized by inflamed, rough skin patches that occasionally produce fluid-filled bumps that may...
Is Impetigo Contagious?
Impetigo is a contagious bacterial infection that usually occurs in children ages 2-5. There are two types of impetigo: bullous...
Jock itch is an itchy red rash that appears in the groin area. The rash may be caused by a bacterial or fungal infection. People...
A keloid is a scar that doesn't know when to stop. When the cells keep on reproducing, the result is an overgrown (hypertrophic)...
Keratosis pilaris (KP) is a common skin disorder in which small white or red bumps appear around hair follicles on the upper...
Lichen planus is a common skin disease that features small, itchy pink or purple spots on the arms or legs. the abnormal areas on...
Melanoma is a type of skin cancer which begins in skin cells called melanocytes and affects more than 53,600 people in the United...
Second Source article from Government...
Moles are small skin growths that may appear flat or raised and are often tan, brown, black, reddish brown, or skin colored. They...
Molluscum contagiosum is a skin disease that causes pink painless bumps on the skin. It typically resolves in six to 12 months....
MRSA (methicillin-resistant Staphylococcus aureus) bacteria causes skin infections with the following signs and symptoms:...
Mycobacterium marinum (M. marinum) is bacteria found in fresh and saltwater that can infect the skin through cuts or scrapes,...
Onchocerciasis, or river blindness, is a parasitic disease that may cause blindness. It is transmitted by the bite of a female...
Pimple vs. Cold Sore
Pimples are areas of skin inflammation with pus in the center. Cold sores are fluid-filled blisters. Pimples are caused by...
Psoriasis is a long-term skin condition that may cause large plaques of red, raised skin, flakes of dry skin, and skin scales....
The word "rash" means an outbreak of red bumps on the body. The way people use this term, "a rash" can refer to many different...
Rheumatoid Arthritis (RA)
Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation of the joints, the tissue around the joints,...
Rosacea is a skin disease that causes redness of the forehead, chin, and lower half of the nose. In addition to inflammation of...
Sarcoidosis, a disease resulting from chronic inflammation, causes small lumps (granulomas) to develop in a great range of body...
Scabies are itch mites that burrow under the skin and produce intense itching that's usually worse at night. Symptoms of scabies...
Scarlet Fever (Scarlatina)
Scarlet fever, a bacterial infection caused by group A Streptococcus bacteria, causes symptoms and signs such as fever, rash with...
Skin cancers occur when skin cells undergo malignant transformations and grow into tumors. The most common types of skin cancer,...
A skin tag is a small benign growth of skin that projects from the surrounding skin. Skin tags can vary in appearance (smooth,...
Sporotrichosis is a skin infection caused by a fungus called Sporothrix schenckii. The fungus, which may be present in sphagnum...
Anabolic steroids are synthetic substances that are related to testosterone and promote skeletal muscle growth and the...
Sweet Syndrome (Acute Febrile Neutrophilic Dermatosis)
Sweet syndrome (acute febrile neutrophilic dermatosis) is a skin condition that sometimes occurs due to an immune system response...
Swollen Lymph Nodes (Glands): Pictures, Causes, Locations, Symptoms, Treatments
Lymph nodes help the body's immune system fight infections. Causes of swollen lymph nodes (glands) may include infection (viral,...
Tuberous Sclerosis Complex (TSC)
Tuberous sclerosis complex (TSC) is a rare genetic disease caused by defects on two genes. The signs and symptoms of TSC vary...
Warts (Common Warts)
Common warts are skin growths causes by the human papillomavirus. There are many types of warts, including plantar warts, common...
Yaws is an infectious disease that mainly occurs in the tropical areas of South and Central America, Asia, Africa, and the...
Other Causes of Bumps on Skin
- Granuloma Annulare
- Intradermal Cyst
- Metastatic Carcinoma
- Polymorphic Light Eruption
- Pyogenic Granuloma
- Rheumatoid Nodules
- Sebaceous (Epidermoid) Cysts
- Sebaceous Gland
- Seborrheic Keratosis
- Soft Tissue Sarcomas
- Splinters or Other Foreign Bodies