The causes of unexplained pain in the patient’s feet are as follows: 1. Gouty arthritis: Mostly due to a large intake of high purine foods, such as seafood and soy products, as well as a large amount of alcohol, which can cause an increase in blood uric acid. When gout crystals gather in the first metatarsophalangeal joint or foot, redness, swelling, heat and pain will appear, especially in the morning when the sudden onset of foot pain, to consider the possibility of gouty arthritis. 2, sciatic nerve pain: for example, lumbar disc herniation, the protruding disc tissue compresses the spinal nerve root, which can cause radiating pain in the lower limbs, and the pain can radiate all the way to the foot. If accompanied by pear-shaped muscle syndrome, it can also compress the sciatic nerve and cause radiating pain in the lower limbs.