This is Sarah Long. And this is Steve Ember with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Stress is a condition of mental or emotional tension. Today, we tell about the effects of stress on people's health.
Many people suffered mental and emotional problems after the September Eleventh terrorist attacks in the United States last year. Terrorism creates fear and fear often leads to severe stress. Studies suggest that stress can reduce the body's ability to fight disease and can lead to serious health problems.
Stress affects everybody every day. It is your body's reaction to physical, chemical, emotional or environmental influences. Some stress is unavoidable and may even be good for us. Stress can keep our bodies and minds strong. It gives us the push we need to react to an urgent situation. Some people say it makes them more productive at work and gives them more energy.
Too much stress, however, can be harmful. It may make an existing health problem worse. Or it can lead to illness if a person is at risk for the condition. For example, your body reacts to stressful situations by raising your blood pressure and making your heart work harder. This is especially dangerous is you already have heart or artery disease or high blood pressure. Stress is more likely to be harmful if you feel helpless to deal with the problem or situation that causes the stress.
Anything you see as a problem can cause stress. It can be caused by everyday situations or by major problems. Stress results when something causes your body to act as if it were under attack. Sources of stress can be physical, such as injury or illness. Or they can be mental, such as problems with your family, job, health or finances. Many visits to doctors are for conditions related to stress.
The tension of stress can interfere with sleep or cause uncontrollable anger or sadness. A person may become more forgetful or find it harder to concentrate. Losing one's sense of humor is another sign of an unhealthy amount of stress.
Stress can lead to many other health problems if people try to ease it by smoking, drinking alcohol, taking drugs, or by eating more or less than normal.
Chronic stress lasts a long time or happens often. Chronic stress causes the body to produce too much of the hormones cortisol and adrenalin. Cortisol is called the "worry" hormone. It is produced when we are afraid. Adrenalin is known as the "fight or flight" hormone. It prepares the body to react physically to a threat.
People under chronic stress produce too much of these hormones for too long. Too much cortisol and adrenalin can result in physical problems and even changes that lead to stress-related illnesses.
Cortisol provides high levels of energy during important periods. However, scientists have become concerned about the hormone's long-term effects on our health. Evidence shows that extended periods of cortisol in the body weakens bones, damages nerve cells in the brain and weakens the body's defense system against disease. This makes it easier to get viral and bacterial infections.
Chronic stress has been linked to high blood pressure and heart disease. Research suggests that people who are easily stressed develop blockages in their arteries faster than other people who are more calm. A recent study of women was carried out in Japan. It found that women who reported high levels of stress were more than two times as likely to die from stroke and heart disease as other women.
High stress levels have been found to cause asthma attacks that make it difficult to breathe. Stress is also linked to mental conditions such as depression and anxiety disorders.
Research also shows that chronic stress reduces the levels of the hormone estrogen in women. This might put some women at greater risk for heart disease or the bone-thinning disease, osteoporosis.
Experts say long-term stress also can weaken your resistance to infections such as colds and influenza, as well as your ability to recover from these diseases. Extended periods of stress are also linked to headaches, difficulty sleeping, stomach problems and skin problems.
Mental and health experts believe personality is an important part in how we experience stress. Personality is the way a person acts, feels and thinks. Many things influence the development of a person's personality, including genetics and experience.
Some people, for example, are aggressive and always in a hurry. They often become angry when things do not happen the way they planned. They are called "Type A" personalities. Studies suggest that these people often get stress-related illnesses.
The "Type B" personality is a much more calm person. These people are able to deal with all kinds of situations more easily. As a result, they are less affected by stress.
Studies show that men and women deal with stress differently. Women usually have stronger social support systems to help them in times of trouble. These social supports may help explain why many women seem to be better able to deal with stress than men are. However, experts say women are three times more likely to develop depression in reaction to the stress in their lives.
Chronic stress is most common among people in the workplace, especially among women. Scientists studying stress in the workplace say many working women are under severe stress because of the pressures of work, marriage and children. Some experts say that pressure can cause a chemical imbalance in the brain that can lead to depression. More than thirty-million American women suffer from depression. These problems are linked to their stress-filled lives and constant hurrying.
People who care for family members who are old or sick also suffer from high levels of stress. Most caregivers in the United States are women. Several studies have been done on people who care for family members with Alzheimer's disease. The studies showed that the caregivers had high cortisol levels in their bodies. This greatly weakened their immune systems against disease.
For example, one study in the United States found that women who cared for family members with Alzheimer's took an average of nine days longer to heal a small wound. The researchers found that the blood cells from the caregivers produced lower amounts of substances that are important for healing and for fighting disease.
Experts say there are several ways to deal with stress. They include deep breathing and a method of guided thought called meditation. They also include exercise, eating healthy foods, getting enough rest and balancing the time spent working and playing. Doctors say people should limit the amounts of alcohol and caffeine in their diets. People who have many drinks with caffeine, like coffee, experience more stress and produce more stress hormones.
Experts say exercise is one of the most effective stress-reduction measures. Running, walking or playing sports causes physical changes that make you feel better. Exercise also improves the body's defense system against disease. And a recent study has found that it helps protect against a decrease in mental ability.
Doctors say deep, slow breathing is also helpful. And many medical studies have shown that clearing the mind through quiet meditation helps you become calm. This causes lower blood pressure, reduced muscle tension and decreased heart rate.
Experts also say keeping stress to yourself can make problems worse. Researchers have linked the inability to identify and express emotions to many health conditions. These include eating disorders, fear disorders and high blood pressure. They say expressing emotions to friends or family members or writing down your feelings can help reduce stress. Experts say people should try to accept or change stressful situations whenever possible. Reducing stress may help you feel better and live longer.
This SCIENCE IN THE NEWS program was written and produced by Cynthia Kirk. This is Sarah Long. And this is Steve Ember. Join us again next week for more news about science in Special English on the Voice of America.