How are you? Knee pain
is a very common symptom which can occur due to a variety of causes
like arthritis, fractures, ligament tears, meniscal tears, chondromalacia, sciatica etc.
Proper evaluation will help in making diagnosis. An X-ray would help in revealing any fractures or ligament tears. With the symptoms that you have mentioned, I feel it is a case of damage to the knee joint due to over use.