Traditional definitions of physical health prior to the onset of modern medicine would have considered someone physically healthy if he or she was not stricken with a serious illness. With modern medical innovations came longer life spans, which changed the way we define physical health. Today's definition can consider everything ranging from the absence of disease to fitness level.

While physical health consists of many components, here is a brief list of the key areas that should be addressed:

• Physical activity - includes strength, flexibility, and endurance
• Nutrition and diet - includes nutrient intake, fluid intake, and healthy digestion
• Alcohol and drugs - includes the abstinence from or reduced consumption of these substances
• Medical self-care - includes addressing minor ailments or injuries and seeking emergency care as necessary
• Rest and sleep - includes periodic rest and relaxation, along with high quality sleep

Physical activity: Most healthy children and adults should be active on a daily basis. This should be a mix of both leisurely physical activity and structured exercise. Examples of leisurely physical activity include hiking, biking, and walking. Examples of more structured forms of exercise include strength training, running, and sports.

Nutrition and diet: A well-balanced diet should contain carbohydrates, proteins, fats, vitamins, and minerals. Restricting specific nutrients should only be done under the supervision of a licensed health professional. Fluid, ideally in the form of clean water, should be regularly consumed. Meals and snacks should be consumed throughout the day, and portion sizes should be sensible.

Alcohol and drugs: Substances that alter mood or other bodily processes should be limited or avoided. Those with addictive tendencies or other health risks should consider complete abstinence from these substances.

Medical self-care: Basic items, such as bandages, lozenges, and over-the-counter pain-relieving medications, should be easily accessible from home. Long-term coughing, fevers, or other ailments should be addressed through primary care. Emergency treatment should be sought when signs and symptoms are significant or life-threatening.

Rest and sleep: While regular activity is essential for physical health, allowing the body to rest is just as important. Spending time relaxing or taking short naps can help rejuvenate the body. Sleep should take place in a quiet, dark environment and should last approximately 7-9 hours. Consistent sleep that is much shorter or longer than this duration, or is low quality, may need to be addressed by a health professional.