The cause of nausea is not known, but some research suggests it may be related to high levels of pregnancy hormones. There are things you can do to try to reduce the nausea and sickness: get plenty of rest; eat little and often; avoid smells and tastes that make you feel sick. Ginger biscuits or ginger tea help some women feel better, as does acupressure at a particular part of the wrist. (This involves wearing wristbands that you can buy from the pharmacy-ask your doctor or midwife for more advice). You should see your doctor or midwife if you can't keep any food or fluid down.
Attribution: BUPA