This article was provided by AccuWeather.com.
Winter brings lower temperatures, snow and many health risks that people may not be aware of.
Knowing some of the unexpected concerns of winter can help you take the necessary steps to avoid them.
1. Raynaud's Disease/Raynaud's Phenomenon
Raynaud's is a disorder marked by a vasospasm, or a narrowing of the blood vessels, in response to cold air that approximately five percent of the U.S. population suffers from, according to the National Heart, Lung, and Blood Institute (NHLBI).
A vasospasm causes blood flow to reduce to the fingers and toes, and occasionally to areas like the nose, ears and lips. During an attack, little or no blood flows to affected body parts according to the NHLBI.
"When I'm having an attack, my fingers, and sometimes toes, will start to feel numb and lose color," Esme Artz, Raynaud's sufferer, said. "They'll turn white and/or gray and either feel tingly or totally numb."
This is part of a three-phase reaction in which the affected body parts turn white, blue, and then red when blood starts to flow back to the area according to the University of California (UC) Davis Vascular Center.
If an attack like this occurs, it is important to take immediate action to warm your body's core temperature so blood flow can regulate again.
"When the symptoms wear off, my fingers, hands and toes usually turn red and burn until circulation has regulated," Artz said.
Although many people are born with or develop Raynaud's for unknown reasons, there are some activities that can directly cause it. They include: repetitive actions that damage nerves, like using vibrating tools such as jackhammers, injuries to the hands and feet and diseases that directly damage the arteries or nerves in the hands and feet, according to the NHLBI.
The best way for people with Raynaud's to avoid attacks is to protect themselves from cold. The NHLBI recommends wearing mittens, hats and scarves in addition to layering clothing.
2. "Christmas Coronary"
According to a study in the International Journal of Cardiology (Int J Cardiol) about variation in cardiovascular events, winter months lead to more deaths by acute myocardial infarction (AMI), or heart attack and stroke.
A study conducted by the European Society of Cardiology (ESC) revealed that AMI increased by 7 percent for each 10 degrees Celsius.
There are multiple reasons for this seasonal pattern of increased Cardiovascular Disease (CVD) and AMI mortality in winter. According to the study by the Int J Cardiol, cold exposure leads to a loss of body heat, increase of metabolic rate and narrowing of the blood vessels which can all contribute to increased cardiovascular problems.
Changes in lifestyle during the winter months is another possible cause for this pattern. People tend to exercise less and eat more during the winter, especially around the holidays. The reduction of these healthy lifestyle choices during the winter can help feed into the "Christmas Coronary" phenomenon.
Another possible cause is the unaccustomed exertion that comes with winter as people who don't usually exercise are forced to shovel their driveways and property.
According to the OJM, coronary deaths in men under 65 years old increased by 85 percent in Toronto due to the unaccustomed exercise of shoveling snow.
3. Trench Foot
Trench foot occurs when people have wet and cold feet for many hours or days, according to Jan Chappel, senior technical specialist at the Canadian Center for Occupational Health and Safety (CCOHS).
"It got its name obviously from soldiers in World War I when they were stuck in the trenches and their feet would be wet all the time," Chappel said.
The common symptoms of trench foot are reddening of the skin, numbness, tingling pain and swelling, according to the National Institute for Occupational Safety and Health (NIOSH).
"You can even get gangrene because your circulation is damaged," Chappel said.
The root cause of this injury is that wet feet lose heat 25 times faster than dry feet, according to the NIOSH.
In response to the lack of heat, the body constricts blood vessels in order to stop circulation to the feet. This causes the skin tissue to die due to lack of oxygen and nutrients, and build up of toxic products, according to NIOSH.
Making sure your feet stay warm and dry so they don't lose this excess heat is the best way to avoid developing trench foot.
Chilblains are the painful inflammation of small blood vessels in your skin that occur in response to sudden warming after cold exposure, according to the Mayo Clinic.
According to the CCOHS, symptoms include redness, swelling, tingling and pain. This damage is permanent, and the redness and itching will return with additional exposure, according to the NIOSH.
Although these symptoms may sound similar to frost bite, there are key differences between the two conditions.
"Chilblains is more small blood vessels, and frost bite is more the skin and body tissues," Chappel said.
It doesn't need to be freezing outside for risk of these injuries. Chilblains can occur at temperatures as high as 60 degrees F, according to the NIOSH, so staying warm and wearing the right clothing at all temperatures is important.
5. Seasonal Affective Disorder
People may experience seasonal depression, or seasonality, as the shorter and colder days of winter approach.
"At the extreme along the continuum of seasonality is full-blown winter seasonal affective disorder (SAD), a syndrome involving recurrent depressive episodes during the fall and winter months with periods of remission in the spring and summer," Kelly Rohan, Ph.D., professor of Psychology at the University of Vermont, said.
The most commonly reported symptoms of SAD include significant fatigue, loss of interest in activities, sleeping more than usual, craving and eating more starches and sweets and gaining at least 5 percent of body weight according to the American Psychological Association (APA).
The cause of these depressionlike symptoms is a shorter photoperiod and decreased exposure to sunlight during the winter months. This shifting absorption of sun leads to higher melatonin levels which can make you feel more fatigued and depressed.
There is no one-size-fits-all treatment available for SAD, but there are multiple methods that have proven to be effective.
The most widely and extensively investigated treatment for SAD is light therapy, i.e., daily exposure to bright artificial light during the symptomatic months, according to the APA.