During the winter, frostbite is a common cause of numb toes, but even in warm weather, hikers aren't immune to numb feet. Pinched nerves and herniated discs are two of the usual suspects. Less often, medical conditions may cause a numb foot. Seek medical treatment to determine the cause of your numbness if it persists.
Frostbite
In cold temperatures, numbness may be a symptom of frostbite. Windy, wet and high-altitude conditions increase your propensity for frostbite, according to the University of Maryland Medical Center. Extremities such as the hands and feet are susceptible to frostbite, as are your nose, cheeks and ears. Other symptoms range from pain and prickling to waxy skin and blisters. In extreme conditions, frostbite can cause gangrene, or tissue death. While hiking in the cold, wear several layers of warm clothing and cover your head to prevent heat loss. Change out of wet clothing and stay well-hydrated to prevent frostbite. Seek medical help if you think you have frostbite.
Raynaud's Disease
The rare blood vessel disorder Raynaud's disease causes constricted blood vessels, which limits circulation and could cause your foot to feel numb or cool. Other affected areas include fingers, noses and ears. Raynaud's disease occurs most often in women age 15 to 40, and typically affects both hands and both feet. Stress and cold can aggravate this condition. Avoid walking barefoot if you have Raynaud's disease. If you suspect you have this condition, talk to your doctor.
Nerve Damage
An injury to the lower back, such as a herniated or ruptured disc, could cause your foot to go numb by damaging a nerve. The area that goes numb depends on the location of the injury. Nerve-related symptoms of a herniated disc range from a tingling feeling or numbness in the leg extending down to the ankle or foot. Aging, disc degeneration and injury can cause a herniated disc. Practicing proper lifting techniques may help prevent back injury, advises the Cedars-Sinai Medical Center. Hikers with back injuries should lift carefully, avoid twisting motions and make sure that their pack fits properly. Tight-fitting shoes could cause your feet to become numb, according to Matt Allyn writing in "Bicycling" magazine. Choose shoes with ample room in terms of width, height and length. If the shoe is too tight in any direction, it could pinch a nerve in your foot, causing numbness.
Compartment Syndrome
Over-exertion at an athletic activity, such as hiking, often causes chronic compartment syndrome, according to the American Academy of Orthopaedic Surgeons. Increased pressure in the muscles disrupts blood flow and can damage nerve and muscle cells. This condition most often affects the calf, but it can also occur in the hands and feet. Pain, cramping and numbness during exercise are symptoms of chronic compartment syndrome. Seek medical attention to determine the cause of your numb foot.
References
- The University of Maryland Medical Center; Frostbite; Steven D. Ehrlich, NMD; August 2008
- Cedars-Sinai Medical Center; Raynaud's Phenomenon; 2011
- Cedars-Sinai Medical Center; Herniated or Ruptured Disc; 2011
- "Bicycling Magazine"; Ditch the Tingles; Matt Allyn
- The American Academy of Orthopaedic Surgeons; Compartment Syndrome; October 2009
