Thank you for asking your query at DoctorSpring.
Your self diagnosis appears to be correct indeed. This swelling is most probably a popliteal cyst or Baker's cyst. In your case this could be due to a synovial fluid leak or bulge from an unaccustomed activity (that is the Yoga posture) .
Yes, you can wait a week or two (or even more if the symptoms are resolving) to see the Doctor. It is difficult to say how long the average healing time is because as you might have already read the cause for this cyst varies. So the healing time also varies. In your case , it could be a month or so. But as I said it depends on a lot of factors.
Till you get medical care you will need to rest the knee. That means no activity that puts knees on strain/impact - No gym, cycling, running. squatting, yoga etc. Avoid prolonged periods of standing and walking too . This will prevent any possible cartilage damage. Your Doctor might ask for an Xray and ultrasound to get to know the cause of the cyst.
You can continue taking NSAID medication Ibuprofen. Compressive bandage might be helpful but I recommend getting it only after consulting your Doctor. If you have sudden severe pain of the knees, pain and/or redness, increasing swelling with or without pain, sudden decrease in swelling (indicates rupture) you should get in touch with your Doctor / ER without delay. These are the warning signs you have to look for.
Hope this helps
Please feel free to ask followup questions.
Patient replied :
Thank you. I'll wait a few days and see how it goes. Will I be able to swim, perhaps? Or some other form of exercise?
Swimming is safer than other form of exercise (as it is low impact on knees). However
I would recommend against doing any kind of exercise (including) in this acute stage, atleast for a
week or two. There is a possible synovial fluid loss. So the knee joint will cartilages
can come in close apposition causing friction and damage. (because of the lack of lubrication).
This can lead on to long term complications like secondary osteoarthritis later in life. The chance for this is less, but still its better to play it safe.