Overall, about 1 in 12 women will contract breast cancer at some age, with the odds higher later in life. But thanks to modern medicine, many breast cancers can be successfully treated with only minor impact. However, the success of that treatment depends critically on early detection, and the earlier the better. One simple way to up the odds of discovery is to perform a regular breast self examination.

The goal of breast self examination is to detect changes which might signal a condition worth investigating more closely, either with a professional clinical exam, mammogram or other diagnostic aid. Those changes might indicate an abnormality. But to judge what's abnormal, it's essential to know what constitutes normal. That varies from individual to individual, though there are commonalities.

The first element to a proper self-exam is to know what your own breasts feel and look like in general. Every aspect of the body changes in subtle ways on a regular basis. During the menstrual cycle those changes may be exaggerated. Breasts can become enlarged or more sensitive. Start your self-exam a few days after your period every month so it becomes a habit. For post-menopausal women, choose the same day every month to perform the exam.

Stand in front of a mirror unclothed and make a visual inspection. Look for changes in the size of only one breast. Normal menstrual cycles and other hormonally related variation will usually affect both the same. Look for any changes in size or color of the nipple or areola (the darker skin around the nipple). Note any wrinkling or 'orange peel' appearance that is not due to cold temperature. Most areola are round. Look for any lack of symmetry.

Squeeze a nipple gently and note any fluid that comes out. Some lactation is normal in some women. But yellowish, pus-like fluid is a reason to call your physician for a closer look. It may be a simple infection or it could be an early sign of a developing tumor. Repeat the procedure for the other nipple.

Continue to look for any such tumors by feeling carefully over the surface of the entire breast with the arms lowered. Take in not just the surface from the breastbone to side, but up toward the armpit as well. Press firmly with the finger pads and move the hand slowly, feeling for any thickening or lumps.

Not all lumps are cancerous. In fact, most are not. A lump may be a simple cyst, a fluid-filled sac of tissue. Often they are round and can be moved slightly. These are benign, though you may want to have them removed anyway. Some will fade spontaneously over time.

Cancerous lumps tend to be harder and less regular in shape. They are frequently attached to breast tissue. Not all hard lumps are cancerous either, so don't be unduly alarmed. Many are just what are called fibroadenomas, a benign clump of cells. Professional tests are required in order to know for sure.

Be particularly aware of any lumps which change in size. Cancer is a malignant, uncontrolled growth of cells in tissue. As such, cancer tumors don't remain static but increase in size and, later, may spread to other parts of the body.

Continue the tactile exam by raising the arms overhead and applying pressure all the way from the breastbone up to the armpit again. Repeat for the other side and breast.

Perform the procedure again while lying down, first with the arms lowered, then raised overhead. Again try to feel any changes, especially tissue which has become hard. The procedure can be repeated in the shower in order to lower friction on the skin, but it can sometimes be difficult to find changes or lumps with water beating on your skin. Try baby oil instead.

Any woman over age 20 should be performing regular breast self-exams, while those over 40 should get a mammogram at least annually.