Causes of a numb foot include fibromyalgia, diabetes, tarsal tunnel syndrome and peripheral artery disease, states Healthline. Foot numbness typically occurs from nerve damage or a lack of blood supply, which can result in conditions such as inflammation, trauma or infection, notes Healthgrades.
Fibromyalgia is tenderness in the tendons, muscles or joints, and is more prevalent in women aged 20 to 50, notes Healthline. Increased blood sugar levels can cause loss of feeling in the legs, increased heart rate and tingling in the arms and legs. Pressure on the nerve and damage to the foot muscles can cause tarsal tunnel syndrome, resulting in numbness and burning sensation in foot muscles. Hardening and narrowing of the arteries supplying feet with blood, or peripheral artery disease, can also cause a numb foot.