A condom is a type of birth control (contraceptive). Condoms are worn during intercourse to prevent pregnancy and the spread of some sexually transmitted diseases (STDs), such as HIV, gonorrhea, and chlamydia.

Other than a vasectomy, the condom is the only available method of birth control for men.

A condom blocks sperm from coming in contact with the inside of the vagina, where it could reach an egg. (If sperm reaches an egg, pregnancy can result.) A condom also prevents disease-causing substances from spreading from one person to another.

Until recently, the condom was used only by men. A female condom is now available.

The male condom is a thin cover that fits over a man's erect penis. Condoms are made of latex rubber, polyurethane, or animal skin. For the best protection, the condom must be put on before the penis comes into contact with or enters the vagina (because pre-ejaculation fluids carry both sperm and disease). The condom must be carefully removed immediately after ejaculation so that no semen leaks out.

The female condom fits inside the vagina. It has two rings to keep the condom in place -- one ring is placed over the woman's  cervix and another one is placed over her vulva. This positioning prevents the condom from being pushed up into the vagina, and creates a protective covering over the outside of the vagina, which prevents sperm from contacting the area.

HOW WELL DOES A CONDOM WORK?

Theoretically, if a condom is used consistently and correctly, it should prevent pregnancy 97% of the time. The actual effectiveness among users, however, is only between 80% and 90%. This is due to:

• Occasional rupture of a condom during intercourse
• Semen spilling from a condom during withdrawal
• Waiting too long to put a condom on the penis (penis comes into contact with vagina before condom is on)
• Break in condom due to manufacturing problems (rare)
• Failure to use a condom during each act of intercourse

How well a condom works to prevent STDs also depends on the above-mentioned factors.

It should be noted that only latex and polyurethane condoms, but not those made of natural animal membranes, effectively prevent the spread of viral infections such as HIV.

Condoms that contain spermicides may slightly further reduce the risk of pregnancy, but they are no more likely to reduce the risk of HIV or STDs than condoms lubricated with other substances.  

CONVENIENCE

• Condoms are available without a prescription
• They are inexpensive
• They can be bought at most drugstores, in vending machines in some restrooms, by mail order, and at certain health care clinics.
• Some pre-planning is needed in order to have a condom handy at the time of intercourse.
• Since the condom must be put on when the penis is erect, but before contact is made between the penis and vagina, there is usually a brief interruption during foreplay. Many couples solve the problem by incorporating the process of placing the condom on the penis into foreplay.

• Provides protection against pregnancy and sexually transmitted diseases.
• Condoms have a slight tourniquet effect on the outer veins of the penis. This may be beneficial for men who have trouble keeping an erection.
• The condom frequently prolongs a man's ejaculation.

• A few men can not maintain an erection after putting on a condom.
• The woman is not aware of warm fluid entering her body (important to some women, not to others).
• Friction of the condom may reduce clitoral stimulation and reduce lubrication, making intercourse less enjoyable or even uncomfortable. (Lubricated condoms may reduce this problem.)
• Intercourse may be less pleasurable since the man must withdraw his penis immediately after ejaculation.
• Allergic reactions to latex condoms are rare, but they do occur. (Changing to condoms made of polyurethane or animal membranes may help.)

• Remove the condom from its package, being careful not to tear or poke a hole in it while opening the package.
• If the condom has a little tip (receptacle) on the end of it (to collect semen), place the condom against the top of the penis and carefully roll the sides down the shaft of the penis. If there is not a receptacle, be sure to leave a little space between the condom and the end of the penis. Otherwise, the semen may push up the sides of the condom and come out at the bottom before the penis and condom are withdrawn. Be sure there is not any air between the penis and the condom. This can cause it to break.
• Some people find it helpful to unroll the condom a little before putting it on the penis. This leaves plenty of room for semen collection and prevents the condom from being stretched too tightly over the penis.
• After ejaculation the condom must be removed from the vagina. The best way is to grasp the condom at the base of the penis and hold it as the penis is withdrawn.
• You should always throw out condoms after use. Keep in mind that flushing a condom down the toilet may clog plumbing. Instead of flushing condoms, you can wrap them in toilet tissue or put them in plastic bags before throwing them in a garbage can. If necessary, put the condom in a garbage can that is out of reach of children and pets.

IMPORTANT TIPS

• Make sure condoms are available and conveniently located. If no condoms are handy at the time of a sexual encounter, you may be tempted to have intercourse without one.
• Carefully withdraw the penis immediately after ejaculation so that semen cannot leak out of the condom as the erection is lost.
• Use each condom only once.
• Do not carry condoms in your wallet for long periods of time. Replace them every once in a while. Friction from opening and closing your wallet, and from walking (if you carry your wallet in your pocket) can lead to tiny holes in the condom. Nevertheless, it is better to use a condom that has been in your wallet for a long time than to not use one at all.
• Don't use a condom that is brittle, sticky, or discolored. These are signs of age, and old condoms are more likely to break.
• If a condom package is damaged, don't use the condom because it also may be damaged.
• Do not use a petroleum-based substance such as Vaseline as a lubricant. These substances break down latex, the material in some condoms.
• If you feel a condom break during intercourse, stop immediately and put on a new one. Remember, ejaculation does not have to occur for a pregnancy to result (pre-ejaculatory fluids can contain active sperm), or for a disease to be transmitted.
• If ejaculation occurs with a broken condom, insert a spermicidal foam or jelly to help reduce the risk of pregnancy or STD transmission. (Do NOT use nonoxynol-9.)
• Store condoms in a cool, dry place away from sunlight and heat.