What Are The Bumps On My Knees? | Causes And Fast Checks

What You’re Feeling And Why It Appears

Knees pack skin, fat, tendons, bursae, and bone into a tight zone. Any can swell or form a nodule. Many are benign and settle with simple steps. Some signal infection or crystals and need quick care. If you’re asking “what are the bumps on my knees?”, start with location and feel.

Common Knee Lumps At A Glance

Use this table to match what you feel with causes.

Cause	How It Looks/Feels	Common In
Prepatellar bursitis	Soft pad over kneecap; tender with kneeling	Floor work, gardeners, athletes
Baker’s cyst	Rubbery bulge behind knee; tight with bend	Arthritis, meniscus tears
Osgood–Schlatter change	Bony bump below kneecap	Active teens
Patellar tendinopathy	Thick, sore band from kneecap to shin	Jumpers, runners
Lipoma	Soft, mobile, painless fat lump	Adults
Epidermoid cyst	Firm, round bump with tiny pore	Hair-bearing skin
Dermatofibroma	Small firm “button”; dimples on pinch	Shins
Wart	Rough, skin-colored; black dots	Kids, swimmers
Folliculitis	Red, pimple-like bump around hair	Shaved, sweaty skin
Gouty tophus	Firm, chalky nodule	Long-standing gout
Rheumatoid nodule	Firm, non-tender lump on pressure point	Rheumatoid arthritis
Bone spur	Hard bump near joint line	Osteoarthritis
Cellulitis/abscess	Hot, red, very tender area	Any break in skin

What Are The Bumps On My Knees? Patterns That Sort Causes

Location, feel, and triggers tell the story. Start by asking “what are the bumps on my knees?” and check location and feel.

Lump Right Over The Kneecap

A soft, squishy pad that flares with kneeling fits prepatellar bursitis. Repetitive kneeling or a direct hit inflames the front bursa. Most calm with rest from kneeling, short ice, and a soft sleeve. Warmth, fever, or marked redness suggests infection and needs same-day care.

Lump Below The Kneecap

A firm bump at the top of the shin in a teen athlete points to Osgood–Schlatter change from tendon pull at the tibial tubercle. Pacing sport, light strength, and time usually solve it. In adults, a tender, thick band from kneecap to shin points to patellar tendinopathy. A slow, graded loading plan beats full rest.

Lump Behind The Knee

A rubbery bulge tight with bending suggests a Baker’s cyst, a fluid pocket from joint swelling. Many shrink as swelling settles. A sudden “pop” with calf pain and swelling can mean rupture and needs a prompt check.

Lump In The Skin

Epidermoid cysts are firm, round, and often show a tiny pore. Squeezing can inflame them; hands off. A dermatofibroma feels like a small button and dimples when pinched; it’s harmless. Warts have a rough top with pepper-like dots. Folliculitis gives small red, itchy bumps around hairs after shaving or sweaty sport.

Hard, Fixed, Or Deep Lumps

Hard bumps near a joint line can be osteophytes. Firm chalky nodules in people with gout are tophi. Large, fixed, or fast-growing masses need an exam and imaging to sort rare from common causes.

Two-Minute Self-Checks

Location

Front over the cap: bursa. Below the cap: growth-plate bump in teens or tendon in adults. Behind the knee: cyst. On the skin: warts, cysts, folliculitis.

Feel

Soft and fluid-like points to a bursa or cyst. Rubber-soft and mobile suggests lipoma. Button-firm with a dimple points to dermatofibroma. Round and firm with a pore leans to an epidermoid cyst.

Triggers

Kneeling or floor work—think bursitis. Jump practice or hill sprints—think tendon. Shaving, tight leggings, or sweaty pads—think folliculitis or warts.

Red Flags

Heat, spreading redness, fever, night pain, weight loss, numbness, a new limp, or rapid growth all earn a same-day appointment.

Home Care Versus Clinic Care

What You Can Try First

Ease the motion that pokes the spot for a few days. Short sessions. A soft sleeve adds light compression. For tendon pain, keep moving with a gentle, steady loading plan. For folliculitis, warm compresses, breathable fabrics, and fast gear changes help. For chafed skin, a plain ointment protects the barrier.

When A Visit Helps

Large frontal bursitis, persistent tendon pain, and big or painful cysts benefit from care. A clinician can drain fluid, check for infection, and tailor care. Teens with a new tibial tubercle bump do well with a paced plan.

Likely Tests

Ultrasound spots fluid pockets and tendon changes. X-rays show bone spurs and the tibial tubercle. MRI maps deeper joint issues when pain or catching lingers. Hot, red swellings may be sampled for bacteria or crystals.

Trusted Medical Sources You Can Use

For frontal swelling that points to bursitis, see the Mayo Clinic explainer on knee bursitis. For a rubbery bulge behind the knee, the NHS page on a Baker’s cyst lays out signs and care. For teens with a bump below the kneecap, Cleveland Clinic’s guide to Osgood–Schlatter is practical. People with chalky nodules can read Cleveland Clinic on gout tophi to understand those chalky nodules.

Everyday Habits That Lower Flare-Ups

Load Smart

Use kneepads or a low stool. Break kneeling into bouts. Swap an impact day for cycling or pool work.

Skin Care

Shave with a sharp blade after a warm shower and with a slip agent. Rinse pads and sleeves, dry them well, and skip sharing gear. Cover scrapes to cut spread.

Strength Routine

Twice weekly, do slow box squats, split squats, and a Spanish squat hold. Keep pain mild. Add gentle quad and hamstring stretches at the end.

Deep Dives By Type

Prepatellar Bursitis

Swelling sits over the kneecap and lights up with kneeling. The bursa can fill from repeated pressure or a blow. Early steps: rest from kneeling, ice, sleeve, and soft pads. If it’s red and hot or you feel feverish, infection is possible and needs drainage and antibiotics.

Baker’s Cyst

This is a fluid pocket that tracks from the joint into the back of the knee. Many cause tightness. A tear or arthritis flare can enlarge it. Treating the joint often shrinks the cyst. A sudden calf swell after a “pop” needs prompt checks to rule out a clot.

Osgood–Schlatter Change

Growing athletes feel a tender bump at the tibial tubercle. Running and jumping tug on the tendon base and the bump grows. Keep sport within a mild pain window, add hip and quad strength, and use short ice. The bump may remain after pain fades.

Patellar Tendinopathy

Pain sits at the lower pole of the kneecap or along the tendon. Deep squats and landings hurt. Isometric holds help pain; slow eccentrics and small jump progressions build capacity. Straps can ease symptoms during training.

Epidermoid Cyst

A round, firm bump with a tiny pore is classic. Squeezing drives contents into tissue and sparks a painful flare. Warm compresses can soothe. Recurrent cysts need the sac removed.

Dermatofibroma

A pea-sized, firm nodule that dimples with a pinch. Often on shins. Removal is only for rubbing or cosmetic reasons and leaves a scar.

Lipoma

Soft, rubbery, and mobile under the skin. Painless and slow growing. These fat nodules can be left alone. Removal is simple if they catch on gear or grow.

Warts

Rough surface with small black dots from clotted capillaries. They spread by contact. Salicylic acid plus gentle paring helps many. Clinic care adds freezing or stronger acids.

Folliculitis

Small, itchy, acne-like bumps around hairs. Heat, sweat, and friction set it off. Warm compresses and loose clothes help. Spreading redness or fever needs a visit.

Gouty Tophi

Firm, chalky nodules near joints in people with long-standing gout. The fix is long-term urate lowering; large tophi may need surgery if they ulcerate or press on tissue.

Rheumatoid Nodules

Firm, non-tender lumps over pressure points in rheumatoid arthritis. They track disease activity. Better control often helps.

Home Toolkit: Quick Guide

Sign Or Situation	Likely Source	Next Step
Soft pad over kneecap after kneeling	Front bursa	Rest from kneeling, ice, sleeve; seek care if hot/red
Bony bump below kneecap in teen	Osgood–Schlatter	Sport pacing, stretches, simple strength
Rubbery bulge behind knee	Baker’s cyst	Ease joint load; scan if calf swells
Round firm bump with pore	Epidermoid cyst	No squeezing; clinic if inflamed or recurrent
Small firm nodule with pinch dimple	Dermatofibroma	Leave alone unless it rubs
Rough bump with black dots	Wart	OTC salicylic acid; clinic for freezing
Cluster of itchy bumps around hairs	Folliculitis	Warm compresses; visit if spreading
Hard bump near joint	Bone spur	X-ray if painful or catching
Firm chalky nodules with gout	Tophi	Urate-lowering plan
Firm nodules with RA	Rheumatoid nodules	Rheum visit to tune control
Hot, red, very tender area	Infection	Same-day care for antibiotics/drainage

What To Expect At A Visit

History And Exam

Plan to answer when it started, what flares it, and if fevers or night pain occur. The exam finds the structure, checks range, and screens for calf swelling.

Tests And Procedures

Ultrasound maps fluid pockets and guides needles. X-rays flag bone spurs. MRI looks deeper if pain persists. A warm, red bursa may be drained. Warts can be pared or frozen. Recurrent skin cysts need removal. Tendon pain gets a load plan; shots are rare.

Key Takeaways: What Are The Bumps On My Knees?

➤ Many knee lumps are benign and settle with simple care.

➤ Location and feel quickly narrow the cause.

➤ Heat, redness, or rapid growth needs same-day review.

➤ Pads, sleeves, and smart loading cut flare-ups.

➤ Hands off skin bumps to avoid infection.

Frequently Asked Questions

Can A Baker’s Cyst Burst And Mimic A Clot?

Yes. A torn cyst can leak fluid into the calf and cause swelling and pain that looks like a clot. That pattern needs prompt checks. Ultrasound is quick and reliable for sorting both.

Treatment targets the joint first. As swelling drops, the cyst often shrinks. Draining or removing a large cyst can help stubborn cases.

How Do I Tell A Lipoma From An Epidermoid Cyst?

Lipomas feel soft and mobile with no pore. Epidermoid cysts feel firmer and often show a small pore on top. Both are benign. Cysts can inflame; lipomas rarely do.

Hands off both. A clinician can remove a cyst sac or a lipoma if it rubs on gear or grows. Sudden growth, pain at night, or a fixed mass needs a review.

Do Warts On Knees Need Treatment Or Will They Vanish?

Many clear in time, but they spread by contact. Salicylic acid plus gentle paring helps. Clinic care adds freezing or stronger acids when bumps are stubborn or sore.

Cover scrapes for sport and avoid picking to curb spread. Dry gear well and skip sharing towels.

My Teen’s Tibial Bump Hurts After Practice. What Now?

That fits Osgood–Schlatter change. Pace running and jumping, use short ice after play, and add hip and quad strength. Keep pain mild during activity and fading after.

Most improve over months. The bump can stay without pain. If daily steps hurt or the knee locks, book a sports-savvy review.

When Should I Worry About A Serious Cause?

Red flags include rapid growth, a hard fixed mass, night pain, fever, weight loss, or a new limp. A hot, red swelling with fever points to infection. A calf swell after a pop behind the knee needs checks for a torn cyst or a clot.

People with a cancer history should get new lumps assessed. Quick sorting gets simple issues back on track and catches rare problems early.

Wrapping It Up – What Are The Bumps On My Knees?

Most knee bumps trace back to a short list: front-of-knee bursitis from kneeling, a tibial tubercle bump in active teens, a back-of-knee cyst from joint swelling, or small skin nodules like cysts, warts, and lipomas. Some reflect gout or rheumatoid disease and respond to condition-level care. Match location and feel, try sensible steps, and book a visit when red flags show. That path turns a mystery lump into a clear, workable plan.