1. Nutritional StressDisease and nutrition are intimately linked. Our food supply has become saturated with processed foods that are largely foreign to the human body. Chiefly derived from wheat and corn, these abnormal foods are the driving force behind obesity, cardiovascular disease, diabetes, digestive problems, cancer, and most all other diseases.

2. Emotional StressA baseline of chronic stress is much more prevalent than most people realize. Chronic emotional stress robs the body of vital energy, suppresses immune function, and disrupts hormonal systems. The cumulative result can be devastating: elevated blood pressure, increased blood clotting, compromised digestive function, elevated blood sugar, chronic sleep disturbances, weight gain and especially suppressed immune function. Uncontrolled stress sets the stage for all diseases.

3. ToxinsThere are up to 200,000 man-made chemicals in the environment that were not present a hundred years ago. Most are petroleum derived. Everyone is exposed and trace amounts can be found in every living creature on earth. The role that toxins play in disease and cancer is hard to absolutely define, but it is certainly a factor. Because toxins can only enter the body by three different pathways (ingestion, breathing, and through the skin), limiting this risk factor is fairly simple.

4. Physical StressThree types of physical stress can affect your body—trauma (wear & tear), temperature, and pressure. Even everyday physical stress (minor trauma, being too cold or too hot, pressure changes) can aggravate established disease processes. For some people, extreme physical stress (severe trauma, severe hypothermia, severe hyperthermia, altitude sickness) can be the primary trigger for allowing disease processes to occur.

5. Free Radicals/InflammationInside each of the trillions of cells that make up your body, free radicals are being continually generated as a byproduct of energy production. Free radicals can damage all parts of the cell, including DNA. It is the most significant factor in aging and contributes to all disease. Other sources of free radicals in the body include abnormal fats from processed foods and toxins. In addition, white blood cells actually generate free radicals to destroy foreign substances in the body; this is the root of inflammation in the body.

6. RadiationLike all living creatures, you are exposed to a certain level of background radiation from gamma rays, x-ray and UV radiation from the earth, sun and space. Though these forms of radiation are a force of disease and aging, exposure from natural sources has been relatively constant since humans began walking the earth. Of greater concern are the increased levels of radiation from artificial and unnatural sources (such as electronics).

7. MicrobesThe role that microbes play in acute disease is well understood. Diseases like strep throat, influenza, malaria, small pox, polio, and the plague cause acute illness in most people who are exposed. Collectively, these aggressive types of microbes (which include viruses, bacteria, fungi, & protozoa) can be referred to as high virulence microbes.

Infectious diseases can be caused by:

Bacteria. These one-cell organisms are responsible for illnesses such as strep throat, urinary tract infections and tuberculosis.Viruses. Even smaller than bacteria, viruses cause a multitude of diseases — ranging from the common cold to AIDS.Fungi. Many skin diseases, such as ringworm and athlete's foot, are caused by fungi. Other types of fungi can infect your lungs or nervous system.Parasites. Malaria is caused by a tiny parasite that is transmitted by a mosquito bite. Other parasites may be transmitted to humans from animal feces.Direct contact

An easy way to catch most infectious diseases is by coming in contact with a person or animal who has the infection. Three ways infectious diseases can be spread through direct contact are:

Person to person. A common way for infectious diseases to spread is through the direct transfer of bacteria, viruses or other germs from one person to another. This can occur when an individual with the bacterium or virus touches, kisses, or coughs or sneezes on someone who isn't infected.

These germs can also spread through the exchange of body fluids from sexual contact. The person who passes the germ may have no symptoms of the disease, but may simply be a carrier.

Animal to person. Being bitten or scratched by an infected animal — even a pet — can make you sick and, in extreme circumstances, can be fatal. Handling animal waste can be hazardous, too. For example, you can acquire a toxoplasmosis infection by scooping your cat's litter box.Mother to unborn child. A pregnant woman may pass germs that cause infectious diseases to her unborn baby. Some germs can pass through the placenta. Germs in the vagina can be transmitted to the baby during birth.Indirect contact

Disease-causing organisms also can be passed by indirect contact. Many germs can linger on an inanimate object, such as a tabletop, doorknob or faucet handle.

When you touch a doorknob handled by someone ill with the flu or a cold, for example, you can pick up the germs he or she left behind. If you then touch your eyes, mouth or nose before washing your hands, you may become infected.

Insect bites

Some germs rely on insect carriers — such as mosquitoes, fleas, lice or ticks — to move from host to host. These carriers are known as vectors. Mosquitoes can carry the malaria parasite or West Nile virus, and deer ticks may carry the bacterium that causes Lyme disease.

Food contamination

Another way disease-causing germs can infect you is through contaminated food and water. This mechanism of transmission allows germs to be spread to many people through a single source.