Knee pain is also associated with toe pain, the possible causes are gout, rheumatoid arthritis, neuralgia caused by the symptoms. 1. Gout: the cause of gout is generally due to the accumulation of uric acid in the body formed by the decomposition and metabolism of purines, hyperuricemia, elevated uric acid will lead to joint pain, in this case, the knee joints as well as toe joints will lead to pain symptoms. 2. Rheumatoid arthritis: it is a kind of proliferative synovitis, which occurs in knee joints, elbow joints, and metacarpophalangeal joints, etc. It can cause localized aseptic inflammation and pain symptoms, and rheumatoid arthritis can also lead to knee pain together with toe pain. 3. Neuralgia: common causes are pectus excavatum syndrome compression of the sciatic nerve, or lumbar disc herniation caused by nerve compression in the spinal canal, if the compression to the control of sensory nerves in the lower limbs, there will be numbness in the lower limbs and joint pain, but also the symptoms of knee pain with toe pain. There may be other causes of knee pain with toe pain, such as systemic lupus erythematosus, etc. It is recommended to consult a doctor as soon as possible for a clear diagnosis and treatment.