Knee pain may arise on account of injury such as torn cartilage. It may arise on account of some medical conditions like gout or infections. Not all cases are serious but the joint damage can worsen if left untreated.

Symptoms:-
1. Stiffness and pain during movement
2. Swelling
3. Pain radiating towards legs
4. Instability
5. Crunching or popping noises
6. Inability to straighten the knee.

Causes:-
1. Injuries
1) ACL Injury
2) Torn meniscus
3) Knee bursitis
4) Patellar tendinitis

2. Mechanical problems:-
1) Hip of foot pain
2) Iliotibial band syndrome
3) Dislocated kneecap

3. Arthritis: - Arthritis can be a major cause of Knee pain.
Types:-
1. Gout
2. Osteoarthritis
3. Rheumatoid Arthritis
4. Pseudogout
5. Septic arthritis

4. Chondromalacia patellae (patellofemoral pain syndrome)

Risk factors:-
1. Excessive weight: - Being overweight can pit excessive stress on the knees and increases the risk of damage to joint cartilage. Day-to-day activities like walking or climbing stairs may also become difficult. It can increase the risk of osteoarthritis.
2. Structural problems: - Physical deformities like flat feet, misaligned knees and length differences between the legs can make oneself prone to pain.
3. Muscular weakness: - Weak and inflexible muscles often fail to support the knee. Stress exerted on the joint cannot be absorbed by these muscles.
4. Sports or Physical activities: - Some sports or physical activities put more pressure on the knees. It can increase the risk of knee injury.
5. Previous injury: - Earlier damage to knee increases the chances of further injury.

Diagnosis:-
1. Physical Exam: - it is performed to check the extent and severity of damage. Any visible occurrence of bruising, tenderness and swelling is carefully examined.
2. Imaging tests: -Imaging tests like MRI/CT scan, ultrasound are performed to reveal the damage caused to bones, ligaments and tendons.
3. Blood tests: - blood tests are administered to check the occurrence of gout.
4. Arthrocentesis:-removing fluid from knee joint and its laboratory analysis.

Treatment:-
1. Medications like pain relievers or NSAIDs
2. Therapy to strengthen the muscles around the knees
3. Arch supports to shift pressure on the knee
4. Corticosteroids injections to reduce pain and provide relief from arthritis flare.
5. Supplemental lubrication to improve mobility.
6. Knee braces
7. Surgery:-
1) Arthroscopic surgery: - To repair damage to torn cartilages and muscles. This surgery is performed by inserting a fiber optic camera through small incisions.
2) Partial knee replacement surgery (unicompartmental arthroplasty):- this procedure involves replacing damaged part of knee with metal or plastic parts.
3) Total knee replacement: - In this procedure, the damaged part is removed and replaced with artificial metal joint.

Self cure:-
1) Rest of a day or two to heal the damage.
2) Ice to reduce pain and inflammation. However, it should not be used for more than 20 minutes else it can cause severe nerve and muscle damage.
3) Compression to support the knee.
4) Elevation to reduce swelling and inflammation.