It’s a chronic pain hence, needs evaluation in terms of clinical examination further supported by radiological investigations like radiographs of Knee and assessment of HKA using scannogram.

since you are having pain since childhood it has to be examined clinically , visit you nearest orthopaedic doctor till then you can take few medicines if you are not allergic to nsaids tab enzoflam 1-0-1 x5 days tab pan 40 1-0-0 x 5 days

Need to assess Hip knee ankle axis as well as strength of your knee muscle and gait Also examination of Hip and flat foot become important

Get evaluated at nearby Orthopedic Surgeon

This treatment is being suggested   on bases of the information provided.  However I would like to examine & investigate you  in detail. -Control  Hypertension, Diabetes or  metabolic disorder, if there is any.  -Any way it may be tried, --. Dolokind Plus (Mankind) [Aceclofenac100 mg +Paracetamol 350 mg] 1 tab. OD & SOS. X 5 days. --. Caldikind plus  (Mankind) 1 tab OD x 10 days. -(You may need help of your local doctor to get these medicines.) --. Fomentation with warm water. Let the part not be exposed to cold. --. Sleep on a hard bed with soft bedding. --. Keep a pillow under the knees. --. Avoid painful acts & activities. -- .Do mild exercises for the back and lower limbs. --.(Take help of physiotherapist or you can visit my you tube channel 'Dr NC Gupta'.)   & see  'me and my yoga'; & 'yoga simplified'. Kindly subscribe to the channel to get notifications for further new information of your interest.  --Do not ignore, let it not become beginning of a major problem. --Do ask for a detailed treatment plan. Kindly make sure, there is no allergy to any of these medicines. --For emergency treatment visit nearest hospital. --Wish you a quick recovery & good health. --I hope, I have solved your problem to your satisfaction.   Dr N C Gupta MS (ortho) DMC 3624  

Consult nearby orthopaedic surgeon for detailed evaluation and management

Get standing knee xray

Need Clinical Examination,Visit Nearest Orthopedic Surgeon