Cancer is the catchall term applied to diseases caused by the uncontrolled growth of abnormal cells. Cancer isn't one disease. It is many different diseases, more than 100 and counting.
Each kind of cancer is usually named for the cell type in which it begins — cancer that starts in a lung is called lung cancer; cancer that starts in pigment cells in the skin, which are known as melanocytes, is called melanoma.
When detected and treated early, cancer can often be stopped. That said, cancer is a leading cause of death and disability around the world.
We can thank the Greeks for the name doctors apply to male hormones. Androgen comes from the words meaning "man-maker," and it's a well-chosen term. Testosterone is the most potent androgen, and it does make the man. It's responsible for the deep voice, increased muscle mass, and strong bones that characterize the gender, and it also stimulates the production of red blood cells by the bone marrow.
In addition, testosterone has crucial, if incompletely understood, effects on male behavior. It contributes to aggression, and it's essential for the libido or sex drive, as well as for normal erections and sexual performance. Testosterone stimulates the growth of the genitals at puberty, and it is one of the factors required for sperm production throughout adult life.
Finally, testosterone also acts on the liver. Normal amounts are harmless, but high doses can cause liver disease and boost the production of LDL ("bad") cholesterol while lowering the amount of HDL ("good") cholesterol.
Studies show smoking high-tar unfiltered cigarettes, as opposed to medium-tar filtered cigarettes, greatly increases your risk of lung cancer. So, cigarettes labeled as low-tar or ultra light are an even safer choice, right? Wrong. A study comparing the lung cancer risks of different types of cigarettes found this seemingly logical assumption is false.
The study six years and involved over 900,000 Americans over the age of 30. The researchers compared the risk of death from lung cancer among men and women who were smokers, former smokers, or had never smoked. When analyzed according to the tar rating of cigarette smoked, the results of the study showed the risk of lung cancer death was greatest for smokers of high-tar unfiltered cigarettes. The risk of lung cancer death was no different among smokers of medium-, low-, and very low-tar cigarettes.
These findings do not come as a complete surprise to researchers. A previous study showed smokers of low-tar cigarettes compensate for the decrease in tar level by changing their inhalation pattern. By blocking ventilation holes in the filter, increasing the drag time, holding the puff longer and deeper, or smoking more cigarettes, addicted smokers may maintain their nicotine intake (and exposure to carcinogens) with low-tar cigarettes.