7. Bl00d Clot or Circulation Issue
Though rare, a blood clot (deep vein thrombosis) in the leg can cause swelling in the knee area, especially if combined with calf swelling, warmth, or pain. It’s a medical emergency and needs immediate attention.

When to See a Doctor
You should seek medical help if:
- The swelling is sudden, severe, or accompanied by fever
- The knee is hot, red, or painful to touch
- You can’t walk or bend the knee
- Swelling lasts more than a few days without improvement
Final Thoughts
One swollen knee isn’t always a reason to panic, but it’s definitely something to pay attention to. From minor injuries to more serious joint diseases or infections, there are many possible reasons. Getting a proper diagnosis is the first step to effective treatment and long-term knee health.
