The common causes of black spots on the soles of the feet are nevus, pigmentation, age spots, melanoma, etc. If there are black spots on the soles of the feet all the time and the black spots protrude from the surface without pain or discomfort, consider them to be nevus. If the foot skin is injured or there is fungal infection on the foot, the black spot will be caused by local pigmentation. After entering old age, due to the slowing down of body metabolism, age spots are easy to appear and can spread all over the body. If there are black spots on the soles of the feet that expand rapidly in a short period of time, and the surface is easily broken and bleeding after rubbing, it may be considered as melanoma. The chance of pigmented tumor becoming cancerous is relatively high, and it is easy to metastasize without timely treatment, thus leading to overall skin cancer. When black spots appear on the feet, usually you should pay attention to observe whether there is rapid growth, easy bleeding and pain when touched, etc. If this happens, you need to go to the hospital in time.