It's quite difficult to judge normal blood pressure. Normal is relative to your particular body, because something that is normal for you may be abnormal for someone else. Therefore it is important that if there is a suspicion someone's blood pressure may be causing them a problem it is investigated very carefully as even small changes in their blood pressure may cause them adverse medical problems

A text book blood pressure reading is normally about 120/80 mmHg. If you repeatedly feel faint and light headed during the day, it's probably a good idea to check with your doctor as to whether you are suffering with low blood pressure.

For some people, low blood pressure can leave them feeling light headed, sluggish or the feeling of a headache. Other people can walk around with low blood pressure and not experience any symptoms. They may only discover they have a low blood pressure when their blood pressure is checked for another reason.

You should also see your doctor if you lose consciousness when you stand, or if you feel repeatedly weak, light headed or constantly tired. Low blood pressure can be a sign in younger people of chronic fatigue syndrome. In older people it can be an indication of more serious problems such as heart disease.

Women in their 40's or younger, may find their blood pressure drop below 90/60 mmHg during pregnancy, dieting or even during the hot weather. So it's important that if they know they are prone to low blood pressure, they have it checked on a regular basis.

If a person is taking high blood pressure medication, it can sometimes cause the blood pressure to drop rapidly which causes the same type of problems. Therefore those taking this type of medication should choose the time of day they take their medication very carefully to ensure the effects are kept to a minimum.