Health is a state of physical, mental, and social well-being. It involves more than just the absence of disease. A truly healthy person not only feels good physically but also has a realistic outlook on life and gets along well with other people. Good health enables people to enjoy life and have the opportunity to achieve their goals.

To achieve and maintain good health, people must have basic knowledge about the human body and how it functions. Only then can they determine what will or what will not help or hurt their health. Learning about health should be a part of everyone’s education.


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Personal hygiene

Society as a whole benefits from people’s good health just as individuals do. For that reason, many government and voluntary agencies strive to preserve and improve the health of all people. The World Health Organization (WHO), an agency of the United Nations, works to promote better health throughout the world.

Elements of physical health

All parts of the body must work together properly to maintain physical health. A person who is in good physical condition has the strength and energy to enjoy an active life and withstand the stresses of daily life. The various practices that help maintain health include proper nutrition, exercise, rest and sleep, cleanliness, and regular medical and dental care.

Nutrition. A balanced diet provides all the food substances needed by the body for healthy growth and development. Nutritionists use the term nutrients for these substances and classify them into six main groups: (1) water, (2) carbohydrates, (3) fats, (4) proteins, (5) vitamins, and (6) minerals. The National Academy of Sciences maintains a list of Recommended Dietary Allowances (RDA), which provides information on how much of each nutrient a person needs each day. Dietary fiber is also important to health, though no RDA has been established for it.


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Different varieties of fruit

A balanced diet consists of a wide variety of foods. Fruits and vegetables provide important vitamins and minerals. Meat, poultry, fish, eggs, dried beans, some dairy products, and nuts are rich sources of protein. Bread, cereals, and potatoes furnish carbohydrates in addition to vitamins, minerals, and fiber.

Good nutrition also includes eating the proper amount of food each day. Overeating can lead to excess weight, which strains the heart and increases the risk of getting such illnesses as diabetes and heart disease.

Many people try to lose weight quickly by following fad diets. But these diets can be dangerous, especially if used over a long period. The safest way to lose weight is to consult a physician or dietitian and follow the program he or she prescribes. Most programs combine moderate daily exercise with a balanced diet that contains a limited number of calories.

Exercise helps keep the body healthy and fit. Vigorous exercise strengthens muscles and improves the function of the circulatory and respiratory systems. Physical fitness benefits both physical and mental health and helps the body withstand stress.

To achieve fitness, a person should start an exercise program slowly and build it up gradually to a level that maintains a healthy heart and strong muscles. Engaging several times a week in such popular activities as bicycling, jogging, and swimming—and even taking long, brisk walks—can furnish the vigorous exercise that is necessary for fitness. Participating in golf, bowling, or some other sport only once or twice a week cannot develop and maintain fitness.

Rest and sleep help overcome fatigue and restore energy to the body. Everyone needs rest and sleep, but the amount required differs for each individual. Most adults sleep from 7 to 81/2 hours a night, though some need less sleep and others need more. Young children may need more sleep at night plus a daytime nap.

Nearly everyone has trouble falling asleep occasionally. However, frequent insomnia (inability to sleep naturally) can indicate various physical or emotional disorders. Therefore, it is best to consult a physician about any frequent sleep problem. Some people take sleeping pills to counteract insomnia. But such drugs can make sleeping problems worse, and they should not be used without a doctor’s prescription.

Rest and relaxation are as important as sleep. After strenuous work or exercise, a person may need a period of total rest. At other times, only relaxation or a change of pace is necessary. Any activity that differs from the normal routine of work or study can be relaxing. Pleasurable and relaxing activities help the body shed tension and remain robust. If rest and relaxation do not relieve fatigue and tension, the individual may have a physical or emotional problem.

Cleanliness controls the growth of bacteria and other germs that can cause disease. A regular bath or shower keeps the body free from dirt and odor. In addition, it helps prevent skin infections that may develop if bacteria grow and multiply on the skin. The hair should also be washed regularly. Daily dental care is another important part of personal cleanliness. Brushing the teeth properly and using dental floss keep the teeth clean and help prevent decay and gum disease.

Medical and dental care. Regular checkups by a physician and dentist play an important role in safeguarding health. Doctors recommend that people seek medical care at the first sign of illness. Early care can result in a quicker cure and lower medical costs. Treating oneself for more than a day or two is unwise unless the condition improves steadily. A physician or medical clinic has the knowledge and special equipment to provide accurate diagnosis and treatment.

Prevention of disease is an important part of medical care. Children should visit a doctor or clinic to receive immunization against chickenpox, diphtheria, measles, mumps, polio, rubella, tetanus, whooping cough, meningitis caused by the bacterium Haemophilus influenzae type b, and hepatitis B. See Immunization.

Elements of mental health

Physical health and mental health are closely connected. Mental health plays an important role in both the way people behave and the way they feel. Emotionally healthy individuals accept themselves as they are—with all their weaknesses as well as their strengths. They remain in contact with reality and can deal with stress and frustration. They also act independently of outside influences and show genuine concern for others.

Emotional development. Experiences during childhood strongly influence a person’s mental health throughout life. An infant is completely helpless at birth and must depend on its parents for all its needs. Children remain dependent for many years, but they slowly mature and learn to do things for themselves. They make many mistakes during this long period of growth and maturation. Through these errors, they learn certain guidelines for relating to other people. Thus, children develop the knowledge necessary to deal with difficult situations in life. This knowledge helps them maintain good mental health throughout life.

Emotional development does not end when a person reaches adulthood. Similarly, an individual’s mental health continues to change from time to time. These changes result from daily circumstances that cause either pleasure or pain for the person.

Handling stress is essential for avoiding both mental and physical illness. Feelings of stress are the body’s response to any threatening or unfamiliar situation. Most severe stress results from such serious events as a divorce or loss of a job. However, stress can occur even in pleasant situations, such as watching a football game or waiting for a loved one to return from a trip. If not handled properly, stress can lead to physical or emotional illness. It may produce only mild symptoms, such as a cough, a headache, or a rash. But severe and prolonged stress can contribute to serious health problems, including high blood pressure and stomach ulcers.

No one can avoid stress, but a person can do certain things to help lessen the danger of becoming ill from it. Regular exercise and sufficient sleep strengthen the body’s resistance to stress. Everyone should learn to relax by resting, taking a walk, meditating, working with a hobby, or by any other method that he or she finds successful. When serious stress occurs, a person should determine the source of the stress and try to eliminate or diminish it. Discussing a problem with a friend, relative, or some other person may also help relieve stress. If these measures are not helpful enough, a mental health professional should be consulted.

Social relationships have an important influence on mental health. Close personal relationships with friends and relatives provide opportunities for communication, sharing, and emotional growth. Such relationships also can provide strength and support for dealing with challenging situations or personal problems.

An individual’s entire social environment also affects his or her mental health. Such social problems as poverty, racism, and overcrowding contribute to situations that influence emotional health. As a result, social and economic changes are needed to help reduce the rate of some types of mental illness.

Health hazards

The nature of health problems in the United States and Canada changed dramatically during the 1900’s. Until then, most people died from infectious diseases, such as diphtheria or pneumonia. Today, however, infectious diseases are no longer the main killers in the United States, Canada, and other industrialized nations. Improved sanitation, immunization programs, and the development of antibiotic drugs have brought these diseases under control. Today, health specialists are chiefly concerned with diseases related to the aging process, unhealthy lifestyles, and environmental hazards.

Tobacco, alcohol, and drug abuse. According to the U.S. Department of Health and Human Services (HHS), cigarette smoking is the principal cause of unnecessary and preventable illness and early death. Heart disease, lung cancer and other lung diseases, and several other types of cancer occur at a much higher rate among smokers than among nonsmokers.

Many individuals use various drugs in an effort to solve their problems or to improve their alertness, mood, or self-confidence. However, the regular use of alcohol, narcotics, or sedatives can lead to addiction and also serious damage to the body. People may become psychologically dependent on a wide variety of other drugs, including amphetamines, cocaine, LSD, marijuana, and tranquilizers. These individuals may harm themselves further by neglecting their health and nutrition. In addition, drugs can distort a person’s judgment and so increase the risk of accidents.

Alcohol is one of the most widely abused drugs in the United States. Millions of people suffer from alcoholism. There is no cure, but the condition can be treated. An alcoholic who gives up drinking can return to a healthy, productive life.

Environmental health hazards caused by modern technology can produce serious problems. Air pollution can worsen the condition of people who suffer from such respiratory diseases as asthma and bronchitis. It may even help cause some diseases, including cancer and emphysema. In some areas, insecticides and industrial wastes contaminate food and water supplies. Excessive noise can also threaten people’s health. Noise from airplanes, construction projects, and industrial plants can cause hearing loss as well as emotional damage.

Occupational health hazards threaten the health of many workers. In some cases, substances involved in a person’s job may cause long-term damage that appears only after many years. For example, many coal miners develop a lung disease called pneumoconiosis, or black lung, from inhaling coal dust. Dust also causes lung diseases among workers in the asbestos and cotton industries. Some industrial chemicals, including arsenic and vinyl chloride, cause cancer. People who work with X rays and other forms of radiation also face a health hazard unless proper precautions are used.

Public health

Public health includes all actions taken to maintain and improve the general health of a community. Government health programs provide most public health services. In addition, many voluntary health agencies receive contributions to combat specific diseases, such as cancer and lung disease. These agencies provide medical services, campaign for health legislation, and make important contributions to health education.

In the United States, the Public Health Service administers the government’s public health programs. State and local health departments also provide a wide range of services in most communities. For example, they work to prevent and control disease by providing proper sanitation, conducting immunization programs, and enforcing quarantines. They also operate clinics that offer free laboratory tests and other medical services to the public. Another important function of public health agencies is to provide health education to individuals, groups, and organizations.