Hello Doctor, I am writing in regards to my 17 year old son who presents with painful knees that seem to have a buildup of fluid. (There is a "squishy" area under the patella, and his knee appears slightly swollen.) His dominant side (right) knee is hurting more. This has gotten progressively worse over the last few days to the point where he is having difficulty walking/bending at the knee and the knees feel very stiff. He also is complaining of a feeling of the knees not getting enough circulation and being cold. He does not feel he can find a comfortable way of sitting/laying down.

This has happened once before, and it took about 2-3 weeks for the symptoms to slowly subside.He was not taking any medications at this time nor did he have any other symptoms.
A doctor examined him and said that there seemed to be fluid there but that it wasn't necessarily the best thing to drain it. My son has a bleeding disorder (Von Willebrands, mild) so I did not want to do this procedure unless it was certain to aid recovery.

He is 6'4, approximately 135 pounds and is not currently active in any type of sports, I would say he is fairly inactive. He is not complaining of any other symptoms anywhere else in his body (such as headaches or fever). He has no previously existing conditions besides the Von Willebrands which has not been a problem before. He does not regularly take any medication on a daily basis-however, about 2-3 weeks ago he started on Vitamin D3 Oral (I believe 10 ml per day/5 drops) for a Vitamin D deficiency (for a 6 week period).

Should he be seen in person by his doctor or would it be best to just rest and ice it?