9781422276136

Influencing Factors The health of the body is affected by innumerable factors. A few of these factors include the sleeping patterns, eating habits, type of diet, food hygiene, stress levels, environmental conditions, and genetic inheritance from the parents. In addition, occupational hazards such as exposure to chemicals and radiation can also lead to several health problems. Disease-Causing Agents Diseases are basically of two types—

infectious and noninfectious. Diseases that spread from one person to the other are known as infectious diseases while the diseases that do not spread from one person to the other are

noninfectious. Microorganisms are small living things that cause diseases and cannot be seen through the naked eye. Various types of microorganisms such as bacteria, fungi, viruses, protozoa, and parasites can cause different diseases in human beings.

SIDEBAR: DID YOU KNOW?

• About 1 in 25 American adults experiences symptoms of serious mental illness in any given year. • Stress can increase the likelihood of developing heart disease, high blood pressure, and irregular heartbeat. That is why doctors call it a “silent killer.”

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