Severe knee pain when i get up&down from any seat, up&down stairs, &trying to get off the floor is nearly impossible.my knees shake it hurts so bad.

Unusual: Late teenage female with severe bilateral knee pain with range of motion has an unusual problem. Absent a history of bilateral knee injury, these symptoms suggest an autoimmune arthritic problem or an inherited problem of joint hypermobility syndrome. A rheumatologist would be the type of medical specialist to consult.

See details: I would urged having the issue evaluated. If the knees are swollen, this is likely to be an inflammatory arthritis. If, not chondromalacia is common in your age group. Get a rheumatologic or orthopedic opinion.