Wednesday 26 December 2012

How winter weather impacts your health


How winter weather impacts your health


       Cold weather brings along a range of problems for our body, from blood pressure to appetite, affecting also our mood. Here is the cost of winter.
The skin is the barrier between the body's internal organs and the environment. In cold weather it redirects the blood flow from the skin surface and the internal organs therefore preventing heat loss. One of the body's ways of staying warm is shivering, the involuntary trembling caused by rapid contraction and relaxation of muscles. But it is also a way to exercise without lifting a finger! In winter the heart works harder, often leading to higher blood pressure. This is particularly dangerous for the elderly vulnerable as they face heart attacks and strokes. Because the skin redirects the blood flow internally, blood vessels constrict and the concentrated blood flow can cause blood clots, which are dangerous were the arteries are restricted.
      According to American researches, we eat about 200 extra calories a day in winter, so we generally gain weight in winter, but we must not blame ourselves for being greedy. In fact we naturally react to the cold by consuming extra calories. Our metabolism is speeded up in winter because the thyroid gland increases its thyroxine output in winter, so that the body can burn more calories.
       Not only we eat more but we need to nap more in winter, it's a natural way to conserve energy in the winter months (animals hibernate and our ancestors were not that busy at the time). Despite evolution so our genes are still programmed for a winter break, hence the need for more sleep. To prevent sleeping we should eat carbohydrates. As days get longer and brighter our the sleeping patterns change and we no longer feel the need for a nap.
      The long winter months take their toll on our immune system, that's why we get colds and related infection more easily. Our whole body works hard in winter and it reacts to the cold as it reacts to stress and this affects our mood too. Winter short days and long nights quite often leave us feeling out of sorts; this is due to lack of melatonin, a hormone triggered by sunlight and it affects our daily body rhythms. Bright lights can help for the brain reacts by it by producing more melatoxin and our spirit will be lifted.

The winter also affects our urge to use the bathroom too:
“The reason is that in order to minimise heat loss during cold exposure the body restricts the flow of blood to the skin and superficial tissues. This is called peripheral vasoconstriction. The result is that blood is shunted to the body core, the volume of blood circulating in the core is higher, and mean arterial blood pressure is higher.
“Blood volume, and hence blood pressure, are regulated by the kidney, which either reabsorbs or sheds water from the body according to how well hydrated we are.
“So when you are exposed to the cold and your blood pressure rises, the kidney interprets this as due to an excess circulating volume, and sets about losing salt and water in order bring down the blood volume and hence blood pressure. As a result you produce more urine.”

Reference: http://www.helium.com, http://healthydecisions.wordpress.com

4 comments:

  1. And extreme cold can cause hypothermia also.
    http://en.wikipedia.org/wiki/Hypothermia

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  2. Severe hypothermia

    As the temperature decreases further physiological systems falter and heart rate, respiratory rate, and blood pressure all decreases. This results in an expected HR in the 30s with a temperature of 28 °C (82 °F).[15]

    Difficulty in speaking, sluggish thinking, and amnesia start to appear; inability to use hands and stumbling is also usually present. Cellular metabolic processes shut down. Below 30 °C (86 °F), the exposed skin becomes blue and puffy, muscle coordination becomes very poor, walking becomes almost impossible, and the person exhibits incoherent/irrational behavior including terminal burrowing or even a stupor. Pulse and respiration rates decrease significantly, but fast heart rates (ventricular tachycardia, atrial fibrillation) can occur. Major organs fail. Clinical death occurs. Because of decreased cellular activity in stage 3 hypothermia, the body will actually take longer to undergo brain death.

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