The hands and feet are the periphery of the body and therefore the surface temperature may often be lower particularly in colder environments. It is not an indication of the core body temperature – the temperature deep within the body’s tissues. Sometimes the hands and feet can be bit colder than the rest of the body even in warm environments and may be nothing more than the body’s temperature regulating mechanisms. However, persistently cold hands and feet especially if it is accompanied by other signs and symptoms needs to be investigated further.
Signs and Symptoms Associated with Cold Hands and Feet
Cold hands and feet may be a sign of various disease both localized and generalized. It should be correlated with other signs and symptoms both of the hands and feet, and elsewhere in the body, before it can be attributed to any specific conditions.
Some of the localized signs that may be present include :
- Paleness of the hands and feet
- Bluish discoloration of the skin of the hands and feet – peripheral cyanosis
- Loss of fine body hairs on the arms and legs
- Dry rough and itchy skin on the hands and feet
- Darkening and thickening of the skin on the lower arms and legs
- Ulcers (open sores), blisters, boils or abscesses
- Swelling of the hands and feet
Normal body temperature of hands and feet
Body temperature is maintained by two main factors – heat generated by metabolism and heat lost through the body’s cooling mechanisms. Most of the heat lost is through the skin and the skin’s temperature may vary during the course of the day while the core body temperature remains constant. Therefore the skin temperature is not a good indication of the normal body temperature and the oral or rectal temperature should be measured for a more accurate reading.
The hypothalamus determines normal body temperature by its temperature-regulating centers. This monitors the temperature of circulating blood in conjunction with feedback from the surface and deep temperature receptors. If the body temperature is too high, the blood vessels in the skin dilate and more heat is passed into the environment. When the body temperature is low, these vessels constrict so that less heat is lost. If the temperature is too low, the body will attempt to increase metabolism and even institute greater muscle activity by shivering so that more heat is generated in the metabolic process.
Apart from the metabolic activity of cells in the hands and feet, the blood is also responsible for distributing heat to these areas. However, the hands and feet are the farthest from the central parts of the body and travel down long thin appendages (the limbs) before reaching the hands and feet. Heat may therefore be lost along the way especially if the environment is cold. If the environmental temperature is close to the internal temperature or greater than it, then the heat lost is minimal or almost none.
Causes of Cold Hands and Feet
Hypothermia is a loss of significant body heat often due to exposure to a cold environment or being immersed in cold water (immersion syndrome). Other symptoms may include confusion, slurring, lack of coordination, shallow breathing, weak pulse and even loss of consciousness.
Frostbite is when the skin and underlying tissue freezes due to severe cold weather. It is more likely to occur with exposure to snow and is preceded by frostnip. It may be associated with direct contact with snow or where there is reduced circulation to the skin in a very cold environment. Frostbite may be associated with hypothermia. Apart from the localized symptoms described above, there may initially be a burning pain followed by numbness and joint and muscle stiffness.
Deficiencies and Malnutrition
Cold hands and feet in these cases may be due to several mechanisms including lower metabolism, reduced circulation, various hormonal disturbances and disruptions in the temperature-regulating centers of the hypothalamus. This may be seen with :
- Iron deficiency anemia
- Iodine deficiency
- Severe dieting
Other signs and symptoms that may also be seen with these conditions include weight changes (gain or loss), dehydration, fatigue and changes in heart rate and/or blood pressure among other clinical features.
Endocrine / Metabolic Disorders
The endocrine system plays integral roles in metabolic functions and this may directly impact on body temperature. In some cases, cold hands and feet occurs secondary to the underlying disease with normal body temperature maintained.
- Addison’s disease / Adrenal insufficiency
- Diabetes mellitus
A number of cardiovascular (heart and blood vessels) diseases may present with cold hands and feet in addition to other signs and symptoms. The change in peripheral temperature may be a result of reduced circulation and/or inability of the peripheral blood vessels to constrict and dilate in response to thermoregulatory mechanisms. With certain acute and serious cardiac diseases, a secondary nervous response may cause vasoconstriction that suddenly reduces blood flow to the extremities.
- Myocardial infarction (heart attack)
- Hypovolemic shock
- Peripheral arterial disease
- Venous insufficiency
- Raynaud’s disease
- Buerger’s disease (thromboangitis obliterans)
Drugs and Other Diseases
Drugs and other diseases may also cause cold hands and feet due to a number of different mechanisms. Skin diseases often compromise the insulating ability of the skin and lead to unregulated loss of heat. Psychogenic factors may cause peripheral vasconstriction and depression can also reduce metabolic activity. Medication may affect the thermoregulatory center in hypothalamus, reduce cardiac output or cause peripheral vasoconstriction. Overdose or poisoning may lead to shock and diminish respiration and metabolic activity.
- Psychogenic – depression, anxiety, fear
- Severe pain
- Medication – amphetamines, epinephrine
- Overdose/poisoning – methamphetamines, ergot poisoning, arsenic poisoning