"Periods can be missed both at the beginning and end of our reproductive life. In the beginning, when we enter puberty, hormones can take a number of months to settle down into a proper rhythm. Much the same thing occurs as we move towards the menopause, and missing periods can be quite common. There are also natural reasons why we do not have periods – for example, during pregnancy and while breastfeeding. However, if you suffer from an absence of periods for more than six months, without any of these natural causes or at these normal times, you can be sure that what you are experiencing is not natural.

What is amenorrhoea?
"The term ‘amenorrhoea’ literally means ‘the absence of periods’. It may seem like a fairly straightforward diagnosis – either you have periods, or you don’t. However, amenorrhoea is not a diagnosed condition, but a symptom of another problem. There are a wide variety of reasons why you may not be having periods, and you must always take steps to find out what is causing your amenorrhoea.
"It’s not normal for women to have no periods, and there will be something at the root of the problem. I have come across many women whose periods have inexplicably stopped. When they visited their doctors, they were told that it was ‘more convenient’ to go without periods, and that there was no reason to look into it unless they wanted to conceive. Drugs could then be offered at that time to stimulate ovulation.
"There is no doubt that periods can be inconvenient, but the plain truth is that it is unnatural not to have them. Your body is designed to have menstrual cycles when you are not pregnant, and if you are not having periods there is something out of balance or unnatural happening in your body. This needs to be investigated and treated. For one thing, if you are not having periods, your risk of osteoporosis is greatly increased.
"Amenorrhoea is classified into two main groups ..."