The immune system also plays a role in restricting tumors and cancerous growths inside the body. It's important to keep your immune system strong and healthy. Here are eight things that can make your immune system weaker.


Stress can have a major negative impact on your immune system. When you experience continued stress, the adrenal glands release extra cortisol to help your body manage the stress. Elevated cortisol levels decrease the production of healthy prostaglandins, which support healthy immune function; while slowed prostaglandin production allows for inflammation, immune suppression, and more. During a period of elevated cortisol levels, immune system cells disappear from the blood. Natural Killer Cells are the part of the immune system most sensitive to increased cortisol levels.

Lack of Sleep

Adequate, quality sleep is essential for immune system health. A study conducted in 2012 found that sleeping fewer than seven hours each night can significantly impair the ability of the immune system to work properly. During sleep, the immune system releases proteins called cytokines. Some cytokines help promote sleep, while others need to increase when you have an infection or inflammation or when you're under stress. Infection-fighting antibodies and cells are also reduced during periods of reduced sleep. The researchers in the 2012 study found a dramatic difference in immune response in subjects who slept four to six hours per night compared to those who slept seven to nine hours. Time was the critical factor, over quality of sleep. School-aged children may need 10 or more hours of sleep for optimal immune system health.

Lack of Exercise

If you are a couch potato and don't get enough exercise, your immune system could pay for your leisure. Studies have shown that exercise boosts your immune system by strengthening the cells in your body that are assigned to attack bacteria. These cells appear to work more slowly in people who do not exercise than in those who do exercise. Your body also produces antibodies during exercise that react to antigens such as bacteria or viruses by hunting them down and destroying them.

Exercise can also potentially help our immune system serve as a "cancer surveillance" system. In one small study, exercise was found to change immune cells into a more powerful disease-fighting form in cancer survivors who had just completed chemotherapy.

Too Much Or "Too Little" Hygiene

Proper hygiene is important to building and maintaining a strong immune system. Studies have shown that children who are exposed to germs may have a stronger immune system and be less likely to develop allergies and asthma in later life. According to some research, a lack of exposure to bacteria early in life can increase a person's vulnerability to autoimmune diseases.

While it's important to get adequate exposure to germs and bacteria early in life, it is just as important to practice proper hygiene as an adult, but for the opposite reason. Good hygiene habits such as brushing your teeth, washing your hands properly before eating, and keeping your hands away from your eyes and nose during cold season can help keep harmful organisms out of your body so that your immune system doesn't become overwhelmed.

Poor Nutrition

The body needs the proper amount of vitamins, minerals, calories and protein for cells to grow and work properly. Without these, the immune system can grow weak and be less able to find and destroy germs. Whether your diet is poor because of food choices, food availability or even poor digestion, your immune system suffers. Good nutrition should include lot of fresh fruits and vegetables, whole grains and low fat milks. A diet that is healthy for the immune system should avoid excessive consumption of refined sugars and highly processed foods containing preservatives, pesticides and chemical additives.

Excessive Alcohol

Just like eating too much sugar, drinking too much alcohol can reduce the ability of white blood cells to kill germs. The more alcohol that you drink, the more damage that occurs to your immune system. Alcohol can impair the ability of the immune cells to function properly, increasing your risk of infectious diseases and cancer.


We have known for a while that smoking can increase your risk of lung cancer. Did you know that smoking, or even second hand smoke, can weaken or damage your immune system? Cigarettes contain more than 4,000 chemicals, all of which are extremely toxic to the body.


Drinking a lot of water is good for your body, and it's also good for your immune system. Staying adequately hydrated can help your body eliminate toxins and waste materials, making your immune system able to better fight infection. Dehydration can also affect your energy levels, as well as your ability to sleep, which can make you less likely to exercise, another trigger for a weakened immune system.

We have one immune system. It's important to keep it strong and healthy and to avoid behaviors that might weaken our immune system. Having a strong immune system can help you fight diseases, infections, and even cancer.

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