Knee Bump Symptoms, Causes & Common Questions

Understand your knee bump symptoms with Buoy, including 10 causes and common questions concerning your knee bump.

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Contents

  1. 10 Possible Knee Bump Causes
  2. Questions Your Doctor May Ask
  3. Statistics
  4. Related Articles

10 Possible Knee Bump Causes

The list below shows results from the use of our quiz by Buoy users who experienced knee bump. This list does not constitute medical advice and may not accurately represent what you have.

Skin cyst

A cyst is a small sac or lump, filled with fluid, air, fat, or other material, that begins to grow somewhere in the body for no apparent reason. A skin cyst is one that forms just beneath the skin.

It's believed that skin cysts form around trapped keratin cells – the cells that form the relatively tough outer layer of the skin.

These cysts are not contagious.

Anyone can get a skin cyst, but they are most common in those who are over age 18, have acne, or have injured the skin.

Symptoms include the appearance of a small, rounded lump under the skin. Cysts are normally painless unless infected, when they will be reddened and sore and contain pus.

Diagnosis is made through physical examination. A small cyst can be left alone, though if it is unsightly or large enough to interfere with movement it can be removed in a simple procedure done in a doctor's office. An infected cyst must be treated so that the infection does not spread.

Rarity: Common

Top Symptoms: skin-colored armpit bump, marble sized armpit lump, small armpit lump

Symptoms that always occur with skin cyst: skin-colored armpit bump

Urgency: Wait and watch

Wart

Warts, also called common warts or verrucae, are small, rough, rounded growths on the top layer of the skin. They may appear alone or in clusters. Common warts are caused by the human papillomavirus (HPV) and are contagious through direct contact. They may spread from one place on the body to another simply through touch.

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Skin abscess

A skin abscess is a large pocket of pus that has formed just beneath the skin. It is caused by bacteria getting under the skin, usually through a small cut or scratch, and beginning to multiply. The body fights the invasion with white blood cells, which kill some of the infected tissue but form pus within the cavity that remains.

Symptoms include a large, red, swollen, painful lump of pus anywhere on the body beneath the skin. There may be fever, chills, and body aches from the infection.

If not treated, there is the risk of an abscess enlarging, spreading, and causing serious illness.

Diagnosis is made through physical examination.

A small abscess may heal on its own, through the body's immune system. But some will need to be drained or lanced in a medical provider's office so that the pus can be cleaned out. Antibiotics are usually prescribed.

Keeping the skin clean, and using only clean clothes and towels, will help to make sure that the abscess does not recur.

Rarity: Common

Top Symptoms: rash with bumps or blisters, red rash, red skin bump larger than 1/2 cm in diameter, pus-filled rash, rash

Symptoms that always occur with skin abscess: rash with bumps or blisters

Urgency: Primary care doctor

Dermatofibroma

A dermatofibroma is a common skin growth that usually appears on the lower legs, but may appear anywhere on the body. These growths are benign (noncancerous). Dermatofibromas are most common in adults and are rarely found in children.

Symptoms include a hard, raised growth that is red, pink, ...

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Pimple

Pimples are also called comedones, spots, blemishes, or "zits." Medically, they are small skin eruptions filled with oil, dead skin cells, and bacteria.

Pimples often first start appearing at puberty, when hormones increase the production of oil in the skin and sometimes clog the pores.

Most susceptible are teenagers from about ages 13 to 17.

Symptoms include blocked pores that may appear flat and black on the surface, because the oil darkens when exposed to the air; blocked pores that appear white on the surface because they have closed over with dead skin cells; or swollen, yellow-white, pus-filled blisters surrounded by reddened skin.

Outbreaks of pimples on the skin can interfere with quality of life, making the person self-conscious about their appearance and causing pain and discomfort in the skin. A medical provider can help to manage the condition, sometimes through referral to a dermatologist.

Diagnosis is made through physical examination.

Treatment involves improving diet; keeping the skin, hair, washcloths, and towels very clean; and using over-the-counter acne remedies.

Rarity: Common

Top Symptoms: pink or red facial bump, small facial lump, painful facial bump, marble sized facial lump

Symptoms that always occur with pimple: pink or red facial bump

Urgency: Self-treatment

Knee Bump Symptom Checker

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Atypical mole

Moles are growths on the skin. They happen when pigment cells in the skin, called melanocytes, grow in clusters. Certain moles are considered "atypical" because of their size and characteristics, which require careful watching and possibly even biopsy in order to monitor for development into cancer.

Rarity: Uncommon

Top Symptoms: severe abdominal lump, brown-colored skin changes, moderate abdominal lump, atypical abdominal bump features, growing abdominal bump

Symptoms that always occur with atypical mole: black or brown abdominal bump, atypical abdominal bump features

Urgency: Primary care doctor

Baker's cyst (popliteal cyst)

A Baker's cyst, also called as Popliteal cyst, is a fluid-filled mass that causes a bulge and a feeling of tightness behind the knee. The pain can get worse when the knee is fully flexed or extended.

Rarity: Uncommon

Top Symptoms: calf pain, swollen knee, knee pain that gets worse when squatting, knee instability, dull, achy knee pain

Symptoms that always occur with baker's cyst (popliteal cyst): lump on the back of the knee, constant knee lump

Urgency: Primary care doctor

Deep vein thrombosis

Deep vein thrombosis (DVT) is a blood clot that forms in a vein deep in the body. Most deep vein clots occur in the lower leg or thigh.

Rarity: Uncommon

Top Symptoms: fever, thigh pain, upper leg swelling, calf pain, butt pain

Urgency: Hospital emergency room

Rheumatoid arthritis

Arthritis is a general term for multiple conditions that cause painful inflammation and stiffness throughout the body. Rheumatoid arthritis (RA) is a chronic condition that is autoimmune in nature, meaning that the body's immune system which normally protects the body by att...

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Infrapatellar bursitis

Infrapatellar bursitis is an inflammation of the bursa, or small cushioning sacs, beneath the patella, or kneecap. The condition may affect either the superficial bursa or the deep bursa.

Superficial infrapatellar bursitis is found in those whose work requires them to kneel on hard surfaces, and so it is known as housemaid's knee, clergyman's knee, parson's knee, or vicar's knee.

Deep infrapatellar bursitis can occur from chronic overuse, as with sports training and other hard physical work.

Either form of the condition can also be caused by hemorrhage, infection, traumatic injury, or inflammatory diseases such as arthropathy. Some cases may be idiopathic, meaning they occur in a particular individual for no clear reason.

Symptoms include swelling of the knee and pain below the kneecap.

Diagnosis is made through patient history and physical examination as well as x-ray, CT scan, or MRI.

Treatment involves rest; heat; nonsteroidal anti-inflammatory drugs to reduce pain and swelling; a knee brace; and sometimes corticosteroid injections into the knee.

Rarity: Uncommon

Top Symptoms: pain in one knee, spontaneous knee pain, dull, achy knee pain, knee pain that gets worse when going up stairs, knee pain that gets worse when squatting

Urgency: Self-treatment

Questions Your Doctor May Ask About Knee Bump

To diagnose this condition, your doctor would likely ask the following questions:

  • What color is the bump?
  • Do you feel pain when you touch the bump?
  • Is your bump getting bigger?
  • Is there anything on the surface of the bump?

If you've answered yes to one or more of these questions

Please take a quiz to find out what might be causing your knee bump. These questions are also covered.

Knee Bump Quiz

Knee Bump Symptom Checker Statistics

People who have experienced knee bump have also experienced:

  • 23% Knee Pain
  • 6% Knee Skin Changes
  • 3% Swollen Knee

People who have experienced knee bump were most often matched with:

  • 80% Skin Abscess
  • 20% Wart

People who have experienced knee bump had symptoms persist for:

  • 39% Over a month
  • 25% Less than a week
  • 15% Less than a day

Source: Aggregated and anonymized results from Buoy Assistant (a.k.a. the quiz).

Knee Bump Symptom Checker

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