Tools of Prevention

Lifestyle and disease are clearly linked. For example, eating an unhealthy diet (high in calories, saturated fats, and trans fatty acids and deficient in certain other nutrients), not exercising regularly, and smoking increase the risk of developing heart disease, cancer, and stroke—the three leading causes of death in the United States. Changing unhealthy lifestyle habits can help prevent particular disorders and/or improve fitness and quality of life. Talking with doctors and other health care professionals can help people make good decisions and establish healthy habits. However, establishing and maintaining a healthy lifestyle can be done only by the person. Consistently eating a healthy diet and getting enough exercise are difficult for many people, but people who do so reduce their risk of developing serious disorders and often feel better and have more energy.

Healthy eating habits can help people prevent or control disorders such as high blood pressure, heart disease, diabetes, osteoporosis, and certain cancers. Recommendations include

• Eating plenty of vegetables, fruits, and whole-grain cereals and breads, partly because such a diet is high in fiber

• Reducing consumption of saturated fats (such as those in butter, cheese, beef, pork, poultry with the skin, and some prepared foods) and avoiding trans fatty acids

• Limiting calories to maintain recommended body weight (see table Body Mass Index (BMI))

• Limiting the amount of salt consumed

Physical activity and exercise can help prevent obesity, high blood pressure, heart disease, stroke, diabetes, some types of cancer, constipation, falls, and other health problems. The best routine includes moderate physical activity for a total of 150 minutes per week, or vigorous aerobic activity for 75 minutes per week (or a combination of the two). Exercise periods should be at least 10 minutes long and ideally spread throughout the week. However, getting even a little bit of exercise is much better than none at all. For example, people who can devote only 10 minutes to physical activity a few times per week may still reap important benefits, particularly if the exercise is vigorous. Walking is one simple, effective exercise that many people enjoy. Certain types of exercise can also target specific problems. For example, stretching improves flexibility, which can help prevent falls. Aerobic exercise may decrease the risk of heart attack and angina.

Quitting smoking

Safe sex practices remain important. Key safe sex practices are avoiding risky sex partners and remaining mutually monogamous. People who have more than one sex partner can greatly reduce their risk of contracting a sexually transmitted infection by correctly using a latex condom every time they have sex. People who are allergic to latex can use other kinds of condoms.

Limiting alcohol use is important. The Centers for Disease Control and Prevention (CDC) recommends that adults of legal drinking age either not drink any alcohol or limit the amount to 2 drinks or less in a day for men or 1 drink or less in a day for women on days when alcohol is consumed. (Each drink is about 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of more concentrated liquor, such as whiskey.) Whether drinking, even small amounts of alcohol, has any health benefits is unclear. Also, drinking even small amounts of alcohol may increase the risk of harmful effects.

Preventing injuries is crucial to maintaining a healthful lifestyle. People can lower their risk of injury by taking certain precautions, such as wearing appropriate protective equipment (including seat belts). For older people,the following can help reduce the risk of falling:

• Removing throw rugs

• Having good lighting at home

• Exercising (especially to improve balance and muscle strength)

• Having vision checked regularly, getting the correct glasses, and wearing them

• Having a doctor, nurse, or pharmacist review all medications that can contribute to falls whenever prescriptions are added or changed

Adequate sleep is also an important part of a healthy lifestyle, particularly affecting mood and mental state. Insufficient sleep is a risk factor for injuries.

Vaccines have been enormously successful. Dangerous and sometimes fatal infectious diseases such as diphtheria, pertussis, tetanus, mumps, measles, rubella, and polio have decreased by more than 99% from their peak number of cases, thanks to the availability of effective and safe vaccines and their widespread use. Furthermore, vaccinations save about $16 in health care costs for every $1 spent.

Many side effects have been attributed to vaccines (see Childhood Vaccination Concerns). Actual side effects that occur depend on the vaccine, but common side effects are usually minor and include swelling, soreness, and allergic reactions at the injection site, and sometimes fever or chills. More serious side effects can occur. They include autoimmune reactions (for example, Guillain-Barré syndrome, which causes temporary weakness or paralysis). However, serious side effects are very rare if vaccines are used appropriately.

Systematic and extensive research has found no link between vaccines and other serious side effects such as autism. Reports that vaccines cause AIDS or sterility are urban legends and have no factual basis. Refusing vaccination to avoid side effects increases the risk of getting an infection, which is a much greater threat to health than are possible side effects of vaccination.

Children and adolescents, older adults, and people whose immune system is impaired are often the most vulnerable to infections that vaccines can prevent. If these people get such infections, they are also often the most likely to have serious symptoms. For example, whooping cough (pertussis) tends to cause severe symptoms in infants but can be as mild as a cold in older, otherwise healthy people. Although it is most important to vaccinate the most vulnerable people, vaccinating other people is also important. Doing so not only prevents illness in the vaccinated person but also reduces the number of people in the community who could develop and thus transmit infection to more vulnerable people. Thus, deaths and serious complications in the community are reduced by vaccinating as many people as possible. This effect is called herd immunity.

Screening is testing of people who are at risk of a disorder but do not have any symptoms (see also Medical Testing Decisions, Screening Tests). Screening can enable doctors to detect a disorder early and to start treatment early. Early treatment sometimes keeps disorders from turning deadly. For example, abnormalities of the cervix or colon can be diagnosed and cured before they become cancerous.

Screening programs have greatly reduced the number of deaths caused by some disorders. For example, deaths due to cervical cancer, once the most common cause of cancer death among American women, have decreased 75% since 1955. However, the decrease varies from area to area, depending on availability and affordability of screening and other factors. Screening can also detect disorders that cannot be cured but that can be treated before they cause too much damage (for example, high blood pressure).

Screening recommendations usually come from government or professional organizations and are based on the best available research. However, different organizations sometimes make different recommendations. There are several reasons for different recommendations. Even the best research results are not always conclusive. Also, screening recommendations must take into account how much risk and how much expense people are willing to accept, factors that cannot be known with certainty. Thus, decisions about screening are individualized. People should discuss screening with their doctor to determine what is best for them.

People may think that any test capable of detecting a serious disorder should be done. Screening can offer great benefits. However, it can also create problems. For example, screening test results are sometimes positive in people who do not have disease. As a result, some of these people then have additional follow-up tests and/or treatments that are unnecessary, often expensive, and sometimes painful or dangerous.

Also, sometimes screening detects abnormalities that cannot or need not be treated. For example, prostate cancer often grows so slowly that in older men, the cancer is unlikely to affect their health before they die from another cause. In such cases, the treatment can be worse than the disease. Another example involves using whole-body computed tomography (CT) to screen everyone for cancer. This approach is not recommended because it does not have benefits (such as saving lives) that exceed the risks (such as developing disorders caused by the radiation exposure, including cancer). In addition, when people are told they might have a serious disorder, they can become anxious, and anxiety can affect health.

Because of these issues, screening is recommended only when

• The person has some real risk of developing the disorder.

• The screening test is accurate.

• The disorder can be more effectively treated when it is diagnosed before symptoms develop.

• The health care benefits of appropriate screening make it relatively cost effective.

Some screening tests (such as tests for cervical and colon cancers) are recommended for all people of a certain age or sex. For people at increased risk because of other risk factors, tests may be recommended at an earlier age or at more frequent intervals than is recommended for people at average risk, or additional tests may be recommended. For example, a person with a family history of colorectal cancer or with a disease that increases the chances of developing colorectal cancer (such as ulcerative colitis) would be advised to have a screening colonoscopy more often than is normal for people at average risk. If a woman has close relatives who have had breast cancer (family history), screening for breast cancer with magnetic resonance imaging (MRI) in addition to mammography may be recommended.

Some screening measures are recommended for people with certain disorders. For example, people with diabetes should check their feet at least once a day for redness and ulcers, which, if ignored, may result in severe infection and ultimately amputation.

Preventive medication therapy (also known as chemoprevention) is the use of medications to prevent disease. For such therapy to be recommended, the person must be at risk of the disorder being prevented and be at low risk of side effects caused by the medication being considered.