The Combined Pill

• headaches
• weight gain or loss
• nausea
• breast tenderness
• bleeding between periods
• mood changes

• the pill may increase your blood pressure
• the pill does not protect you against sexually transmitted infections so you may need to use condoms as well

A very small number of women may develop a blood clot that can block a vein (venous thrombosis) or an artery (arterial thrombosis or heart attack or stroke). If you have ever had a thrombosis, you should not use the pill. Some types of pill appear to be associated with a slightly higher risk of venous thrombosis.

The risk of venous thrombosis is greatest if any of the following apply to you: you are very overweight; are immobile (use a wheelchair); have severe varicose veins, or a member of your immediate family had a venous thrombosis before they were 45.

The risk of arterial thrombosis is greatest if any of the following apply to you: you smoke; have diabetes; have high blood pressure; are very overweight, or a member of your immediate family had a heart attack or stroke before they were 45.

Research shows that women who take the combined pill have an increased risk of being diagnosed with breast cancer. This risk disappears over a ten-year period after stopping the pill. Studies are being done to see why this occurs, and how it relates to pill use, or if women taking the pill are diagnosed earlier than women who don't take the pill.

There is also some research to suggest a link between using the pill and developing cervical cancer, as not using a barrier method of contraception increases your chance of exposure to high-risk strains of the human papilloma viruses (HPV) that are the underlying cause of cervical cancer.

Some research suggests a link between using the combined pill and developing a very rare liver cancer.

Over the years the pill has often been blamed for side-effects that were due to other causes. For most women the benefits of the pill outweigh the possible risks.

See a doctor straightaway if you have any of the following:

• pain in the chest, including any sharp pain which is worse when you breathe in
• breathlessness, or you cough up blood
• painful swelling in your leg(s)
• weakness, numbness, or bad 'pins and needles' of an arm or leg
• severe stomach pains
• a bad fainting attack, or you collapse
• unusual headaches or migraines that are worse than usual
• sudden problems with your speech or eyesight
• jaundice (yellowing skin or yellowing eyes)