Your period is a bleed from the vagina that happens approximately every 28 days (between 24 and 35 days is common).
Your periods will usually start somewhere between the ages of 9- 16 years, most commonly between 12 and 13 years. They continue until the menopause, which is usually between 45 and 55 years.
As a baby girl you are born with all your eggs stored in follicles (sacs) in your ovary . As puberty begins, your body begins to produce hormones that cause your eggs to mature. This is the beginning of your first menstrual cycle .
Having periods is part of the female reproductive cycle. Your cycle begins on the first day of bleeding and continues up to, but not including, the first day of your next period.
During a cycle various changes occur in your body. These are caused by the variations in the amount of various hormones, which are produced by your body at different times of your cycle.
As your follicles within your ovary ripen they secrete the female hormone oestrogen. This causes your womb lining to thicken and cervical mucous (mucus produced by the cells lining the cervix) to change. As levels rise, this will then cause an egg to be released from your ovary (ovulation), which will travel down your fallopian tube and into your womb.
Ovulation takes place approximately 14 days after the first day of the start of your last period, however, this timing can vary greatly. When you are ovulating your temperature will rise by approximately 0.5 degrees Celsius. This temperature rise can be measured. It should be taken at the same time every morning before getting out of bed.
If this egg is not fertilised through sex it will naturally disperse and the lining of your womb (endometrium) will be released.
The female hormone prostaglandin then kicks in causing your womb to contract. This marks the beginning of your period.
The bleeding is composed of the womb lining, together with some blood caused by the breaking of fine blood vessels within the womb as the lining detaches itself.
Bleeding can last up to 8- 10 days but commonly lasts about 5 days, with the bleeding heaviest on the first 2 days.
Your blood flow may appear very heavy but blood loss will normally only fill about 5- 10 teaspoons in total.
The cycle of your hormones may affect you emotionally. There is a tendency for you to feel more relaxed and confident until the ripe egg is released from your ovary (approximately day 14) After this you may have some symptoms of pre- menstrual tension e.g. headaches, bloating, irritability and tearfulness.
Periods can sometimes be painful because of the female hormone, prostaglandin, which causes your womb to cramp. This cramping may start a day before your period begins and last for a few days. This can cause pains in your abdomen and in your vagina and back.
You may also feel nauseous, have a headache, feel generally tired and sweaty. However some women have few or no symptoms.
To relieve the discomfort of your period you can take painkillers. Ibuprofen and aspirin can be particularly effective. Take the recommended dose regularly throughout the day.
Do not drink drinks containing caffeine, such as coffee, tea, cola or cocoa.
Exercise is a good natural way to ease pain. Gentle walking, swimming or cycling are often very effective.
Relaxation techniques, massage and generally avoiding stress appear to also help relieve period pain.
You may also find that holding a hot water bottle or heat pack (warmed in the microwave) on to your abdomen or back reduces discomfort.
source NHSDirect 151204