Cold Intolerance

As mentioned above, cold intolerance is a symptom rather than a disease. The underlying conditions that can cause cold intolerance include:

• Hypothyroidism: This occurs when your thyroid gland is not able to produce enough thyroid hormone. The hormone drives metabolism and is responsible for providing energy to the body. A lack of thyroid can lead to obesity, fatigue, slowed heart rate, slow reflexes, stiff joints, high blood cholesterol and all these factors can lead to hypersensitivity to cold. Those over 60 are more likely to suffer from hypothyroidism which may be caused by autoimmune disorders.
  If hypothyroidism is identified as the underlying issue, you will likely be prescribed medication that will mimic the function of the thyroid and raise levels back to acceptable limits. Treatment usually does manage symptoms and is lifelong. It will take several weeks before you start to feel the effects, however, as the hormone takes time to build to effective levels. 
• Blood vessel diseases: Raynaud’s disease is characterized by numbness in the extremities in cold temperatures. It is caused by the narrowing of blood vessels that limits the amount of blood that flows to the extremities; in severe cases, fingers and toes go blue and become painfully stiff. It is more common in colder environments, and for unknown reasons, is nine times more likely to affect women than men. The causes are not well understood, but it is believed that it is caused by an overactive sympathetic nervous system that causes blood vessels to narrow too much in response to the cold. Past injuries, carpal tunnel syndrome, and other blood vessel disorders can also increase the likelihood of Raynaud’s. Vasodilators are usually used to treat more serious cases since they widen blood vessels and can ease symptoms. 
• Anaemia: Anaemia is caused when the body does not have adequate red blood cells. RBCs carry oxygen to various parts of the body which is central to carrying out chemical reactions that sustain life. There are many types of anaemia, but the most common types are caused by iron or vitamin deficiencies. Sadly, many poor Indian mothers are often anaemic because they do not get adequate nutrition. Blood tests will reveal specific nutritional deficiencies, and iron and vitamin supplements are usually effective in reversing anaemia.
  However, other types of anaemia, such as aplastic anaemia, and anaemia caused by inflammation or various cancers require more involved interventions and take a longer time to resolve. 
• Fibromyalgia: Fibromyalgia is characterized by widespread pain which causes sleep issues along with fatigue and depression. Sometimes, trauma can have a lingering effect in terms of overall pain and lead to fibromyalgia. In other cases there is no triggering event and symptoms build up over time. It is not known what causes the disorder, but genetic reasons seem to play a role since it is often seen within families. Damage to neural pathways may explain it in part as well; neurotransmitters can become easily stimulated and trigger responses to pain even when it is absent.
  There is no cure for fibromyalgia but painkillers and antidepressants can bring relief from symptoms. 
• Anorexia nervosa: Anorexia nervosa is a complicated and severe eating disorder wherein people avoid eating to the point of near starvation. There is a pathological fear of gaining weight and body image issues that cause those affected to limit caloric intake or induce vomiting to reduce the absorption of food. The causes of anorexia are complicated, but there is evidence for genetic mutations, psychological issues and cultural mores playing a role. Anorexia will lead to a host of health complications similar to starvation and cold intolerance will be one of them.
  There is currently no medicine that is known to help with the situation and hospitalization is required. 

Since cold intolerance is a symptom of an underlying condition and not a disease itself, your doctor will conduct a thorough physical exam. You may also be asked to give your medical history, including your family's medical history, underlying conditions, medications, duration and onset of symptoms, and lifestyle questions as well. Often the case is that you will go to the hospital to get a consultation about an underlying condition and cold intolerance will figure into the conversation as a peripheral issue.

Depending on your overall symptoms and history, your doctor will conduct relevant diagnostic tests. If hypothyroidism is suspected, for example, blood tests will be conducted to check for levels of TSH or thyroid-stimulating hormone (TSH test), whereas if iron deficiency based anemia is suspected, bloodwork to check for iron levels will be conducted. 

In summary, since cold intolerance can be caused by a variety of conditions, you must do your best to articulate symptoms to your doctor so that the right diagnosis can be made.

Treatment is entirely dependent on the underlying condition. However, there are some lifestyle changes that can be incorporated such as maintaining a balanced diet and exercising regularly. It is sometimes the case that cold intolerance is a reflection of poor overall health.