Look for dimpling of the skin, redness, or any change in the contour of your breast. Examine your breast lying down. If you have large breasts, put a pillow under your back to flatten your breasts. Use your left hand to examine you right breast and vice versa. Use the flat part of your fingers to check for lumps or unevenness in texture.
Some women start at the nipple and work outwards in, increasing circles.
Other women prefer to go up and down, starting at one side and working towards the other. The diagram that comes with the material from the American cancer Society is very helpful, and I would recommend getting the information from them. Sometimes it is diagnosed just by the characteristics history and examination. Sometimes an ultra sound or, in older women, a mammogram may be performed. We start using mammograms in women in their mid thirties and up.