Question 1

What is a Baker's cyst?

Accepted Answer

A Baker's cyst (popliteal cyst) is a fluid-filled sac that bulges out from the back of your knee joint. It occurs when excess joint fluid (from arthritis, meniscus tear, or other knee problems) pushes into a natural space behind the knee. Think of it like a water balloon connected to your knee joint - when the joint has too much fluid, some pushes into the balloon.

Question 2

Is a Baker's cyst dangerous?

Accepted Answer

No, Baker's cysts are not dangerous and not cancerous. They're a sign of an underlying knee problem, but the cyst itself won't harm you. The main concern is finding and treating whatever is causing excess fluid in your knee (arthritis, meniscus tear, etc.). Rarely, a cyst can rupture and cause sudden calf pain/swelling that mimics a blood clot.

Question 3

Will the cyst go away on its own?

Accepted Answer

Sometimes. If the underlying knee problem resolves (meniscus heals, arthritis improves with treatment), the cyst may shrink or disappear. However, if the underlying problem persists, the cyst usually persists too. About 20-30% of cysts resolve spontaneously over months to years, but many remain indefinitely.

Question 4

Should I have it drained?

Accepted Answer

Usually no. Aspiration (draining with needle) provides only temporary relief - 80-90% of cysts refill within weeks to months because the underlying knee problem persists. It's rarely recommended unless the cyst is very large and painful. Focus on treating the underlying knee problem instead.

Question 5

Do I need surgery?

Accepted Answer

Rarely. Surgery is only considered if: 1) The cyst is very large and painful, 2) Conservative treatment has failed, 3) There's an underlying knee problem that needs surgery anyway (like meniscus tear). Even then, treating the underlying knee problem is more important than removing the cyst. Most Baker's cysts never need surgery.

Medical Disclaimer

Baker's Cyst (Lump Behind Knee)

📖What is Baker's Cyst (Lump Behind Knee)?

🔬What Causes It?

⚠️Risk Factors

You may be at higher risk if:

🛡️Prevention