How are they connected?
When you think about weather, you’re most likely concerned with whether or not your need to bring an umbrella or coat with you when you walk out the door. When you think about seasons, you’re probably thinking about the different activities that you enjoy doing during each one. The last thing that you might associate with either of these is health. But, did you know that both of them can impact your health?
The impact of weather affecting health has been recorded as far back as 400 BC. Even back then, people were complaining that the changing weather made their joints hurt. In order to understand how weather and seasons impact your health, it’s essential to understand the difference between the two. Weather is the short-term state of the atmosphere at a specific time in a specific place. It includes temperature, humidity, cloud cover, precipitation and wind. Weather can change every day or sometimes throughout a day. Each season represents one of four division of the year (spring, summer, fall and winter). During each season, we tend to expect certain types of weather. In the summer, we expect it to be hot; whereas, in the winter we expect it to be cold. We typically associate spring with rain and temperatures starting to warm up and associate fall with leaves changing color and temperatures cooling down. In some ways, weather and seasons are interrelated and changes in both can impact your health.
A big component of weather that impacts your health is atmospheric, or barometric, pressure. Atmospheric pressure is the weight of the air against other objects and is always there. However, warm air causes atmospheric pressure to increase and cold air causes it to decrease. These changes are what cause a variety of health conditions. When there’s a decrease in atmospheric pressure, the gas inside your body can expand, including the gas in the fluid around your joints. This sudden expansion of fluid can put more pressure on old injuries that didn’t heal 100% and result in pain in your joints. This same concept is why you’re more likely to experience headaches or migraines when the weather is cooler. One important thing to note is that older people are less able to physiologically adapt to sudden shifts in atmospheric pressure or temperature, especially those who have diabetes, hypertension, heart problems or lung diseases. This means that they are at an increased risk of dying when these weather changes happen.
Cold temperatures also impact your cardiovascular system in a variety of ways. One huge impact is that your blood flow slows when the weather is cold, which makes it harder for your heart to get oxygen-rich blood throughout your body. This is one of the reasons why there are more heart attacks in winter. Another issue is that many people don’t exercise as much in the winter and then need to clear snow from their sidewalk and driveway, which is very physical activity. This puts even more strain on your heart. A significant issue if you’re a diabetic when your blood thickens due to a cool down in temperature is that you might have a harder time keeping your blood sugar at stable levels. The reduction in blood flow also effects the small blood vessels in your skin, fingers and toes. They become narrower, which reduces the delivery of nutrition and oxygen. This decrease means that your hair and nails are weaker and more likely to dry out. Since colder air is also drier air, it can make it harder to breathe. This is because the cold, dry air reduces the amount of healthy mucus that is supposed to coat in the inner linings of your respiratory tract and causes small cracks to form in the lining of your bronchial tubes, which makes it hard and painful to breathe. This drying out process also impact your sinuses, which leaves you more susceptible to germs because there isn’t as much mucus to prevent them from entering your body. The other reason why you’re more likely to catch a cold or the flu during colder months is because dry, cold air allows the viruses who are responsible for these illnesses to survive longer and transmit more easily. There’s research to suggest that the virus’ exterior coating becomes tougher when the temperature is closer to freezing, which means the extra strength helps viruses be more active and resilient. This is why the rhinovirus (main cause of the common cold) cases peak in the spring and fall when the temperatures are cooler and the flu viruses peak in the winter. The other factor to this is that when it’s cold outside, we tend to spend more time together indoors, so we’re more apt to spread germs to each other.
Once spring arrives, the temperatures start to warm up and you’re relieved that the cold weather is finally gone. However, spring comes with its own set of medical issues. A big one that most people experience are seasonal allergies. Allergies and asthma have a very well-established connection to weather changes. Often, they are triggered pollinating plants. There are different types of pollen based on which plants are pollinating throughout the year. Treating seasonal allergies is key because it can help keep mucus in your nasal passages at the right level to do their virus-catching job better. Recurrent allergy problems can even lead to secondary bacterial infections in your sinuses, which can make you feel like you’re spending weeks or months battling the same cold. In order to prevent this from happening, there are some steps you can take to help prevent you from becoming sick, like washing your hands regularly, getting plenty of sleep, eating a well-balanced diet, exercising, keeping stress under control and getting your flu shot. Remember, if you do catch a cold, or during winter months when the air is dry, moist air will feel more comfortable for you to breathe, so it can be helpful to invest in a humidifier. One thing many people don’t realize is that suicide actually increase in the spring and early summer. One theory is that the sudden warmth of spring and summer can create mania, which increases risk. Another theory is that since spring makes inflammation problems worse, and there’s a known correlation between suicide and inflammation, this is a contributing factor. A final theory is called the “broken promises” theory. The concept is that you expect to feel bad during winter and better during spring. So, when spring comes and this doesn’t happen, you become even more depressed since the assumption is that everyone is supposed to feel happy in warm weather.
Summertime comes with health issues that you should be aware of though. When it’s hot and humid outside, the air often feels heavier. This can make breathing difficult, especially for those who already have respiratory issues. If you live in an area where there is air pollution, it makes it even more problematic to breathe. People are often more active during summer and frequently end up injured. Also, people don’t usually drink enough water when they are participating in outdoor activities and can become dehydrated quickly. The number of people who are hospitalized for diabetes-related problems increases in hot weather. This is because individuals with diabetes have trouble managing their blood-sugar levels. When you have problems with your blood-sugar levels, you might have a harder time producing sweat to cool down and you might need to urinating more frequently. This makes it more likely for a diabetic to become overheat or dehydrated. Another factor to consider is that during late spring and summer is the increase in violent crime, particularly murder, spikes. There are several theories as to why this is the case, but it’s thought to be related to the fact that more people are outside and the days are longer, so there is more opportunity for crime. Despite the higher rates of violent crime, there is some research that suggests a correlation between warmer climates and lower death rates.
As seasons change into fall, the air starts to get cooler and the days are getting shorter. This results in you feeling sleepier and groggier during the day. For some people, hypersomnia, which is the exact opposite of insomnia, peaks at this time of year. You sleep more, but you feel less rested. Seasonal affective disorder (SAD) is a form of low-grade depression that usually happens when days start getting shorter and exposure to natural sunlight diminishes. Light therapy is often effective at treating SAD, but it’s also a good idea to maintain a healthy diet, exercise often and talk to your doctor about other treatment options. It’s important to note that if you’re in a good mood and dealing with bad weather, you’re less likely to end up in a bad mood. However, if you’re already feeling crummy, a cold, dreary day can easily cause your mood go from bad to worse.
Did you know that the way your DNA functions, called gene expression, changes as the seasons do? It is thought that about 5,000 genes in blood cells undergo seasonal changes in expression. While every cell in your body has the same genetic code, each type specializes in certain parts of that code. This is controlled by how tightly your DNA is wound around structures called histones. This isn’t the twisted double helix that you’re thinking of, but more like coiling up a cord. The outside of these coils are coated in molecules called methyl markers. Under certain circumstances, the methyl markers instruction a gene to uncoil. Then, that section of the gene is exposed to messenger RNA, which uses the DNA code to make proteins. These proteins are used throughout your body to carry out specific functions. Scientists don’t know yet what triggers these seasonal changes. They are thinking that it’s probably something environmental, like length of daylight or temperature. In the winter and early spring, when the weather is colder, the proteins cue the amount of inflammation in your body to increase, which increases your immune system response in order to help your body be better equipped to fight off illnesses. In the summer, your cells are instructed to retain water and burn fat. Another interesting fact is that you’re more likely to conceive a boy during summer months and more likely to conceive a girl during winter months.
Changes in weather are basically challenges to your body. Your body gets used to a certain climate, and when those things change suddenly, it has to try to adapt. Unfortunately, sometimes it has a difficult time adjusting and this can trigger an illness. It has been proven that warmer average temperatures in the winter and lower average temperatures in the summer are correlated with increased happiness. When winters are milder and summers are cooler, it makes it easy to get outside throughout the year, which facilitates physical activity, lowers stress levels and increases well-being. However, one thing that has scientists concerned is how climate change is contributing to rising global temperatures and the higher risk of extreme weather events in the future. This could take a toll on your mental and physical health. For people, living in high-risk areas for extreme weather events, such as hurricanes, tornadoes, floods and tsunamis, their risk for physical and mental stress increases significantly. This isn’t just because of the events, but the recovery after the fact. The National Wildlife Federation estimates that about 200 million Americans are at an increased risk for psychological distress, including stress, anxiety-related disorders, substance abuse and suicides, because of climate-related issues. Other research is suggesting that warmer global temperatures as a result of climate change would also increase rates of disease and death.
There’s no question that weather and seasons play a significant role in our health down to the molecular level. By having an understanding of how they impact your body, you’ll be able to be better prepared to deal with any potential illnesses. As our climate is continuing to transform, we need to expect that more extreme health events are going to be on the rise and be ready to deal with these changes.