Heart disease
For example, when your immune system is not being properly regulated, your arteries get inflamed and cells build up on artery walls. Blood can't get through and you could have a heart attack.

Stress also affects your heart when it prevents you from eating well and keeps you from exercising. Doctors know that women who exercise 30 to 60 minutes most days of the week, quit smoking, and eat a diet high in fibre, omega-3 fatty acids and folate (and low in saturated fat, cholesterol and salt) have a lower risk of heart disease.

One scientific study of 30,000 people in 52 different countries, says Bacon, found that being stressed was the third most important risk factor for a heart attack -- even more significant than having high blood pressure.

Cancer
"Cancer, too, is an immune disease," says Bacon. When your immune system works as it should, it spots normal cells that are turning into cancer cells and destroys them before they can spread. But when chronic stress affects your immune system, existing cancerous cells can grow and new ones may even develop.

And just as for heart disease, a healthy lifestyle can prevent cancer. Watch that stress doesn't prevent you from maintaining a healthy weight -- there's a well-known link between obesity and breast and ovarian cancers. And if stress leads you to drink more -- you should note that more than one alcoholic drink per day raises your risk for mouth, throat and liver cancers.

Asthma and allergies
A stressed immune system can also cause asthma and allergies when your body reacts to substances that are usually harmless. In addition, when you're not looking after your health, you may fail to take preventative medications, opening yourself up to unnecessary asthma or allergy attacks.

Arthritis
An overwhelmed immune system can start to attack the body's own organs. This is what happens with rheumatoid arthritis. In general, says Bacon, people who are chronically stressed are more likely to develop arthritis and among people who have arthritis, those who are stressed tend to have the worst cases.

Exercise helps an arthritis sufferer because it strengthens bones, muscles and tendons, all of which support joints. But it can be difficult to exercise when depressed -- which is the case for about one fifth of people with rheumatoid arthritis. Doctors have found that when the depression is treated, the arthritis improves as well.

Click to continue to how stress influences diabetes, plus coping tips...

Page 2 of 3