Stress symptoms may be affecting your health, even though you might not realize it. You may think illness is to blame for that irritating headache, your frequent insomnia or your decreased productivity at work. But stress may actually be the cause.Common effects of stressIndeed, stress symptoms can affect your body, your thoughts and feelings, and your behavior. Being able to recognize common stress symptoms can help you manage them. Stress that's left unchecked can contribute to many health problems, such as high blood pressure, heart disease, obesity and diabetes.