A late/missed period may primarily be a sign of pregnancy, and this can be confirmed with a pregnancy test. It can also occur if the woman is currently breastfeeding, or on a contraceptive, as these can cause irregular periods. However, if this is not the case, it may be due to oligomenorrhea (irregular periods) or amenorrhea (no periods), both are a type of menstrual disorder. Primary amenorrhea is when a woman fails to begin periods at the expected age, and secondary amenorrhea is when periods cease. There are many causes for both of these conditions, however having a late/missed period is not always an indication of underlying disease.
The period is late or doesn't appear at all.
One common cause for a late/missed period can be if you have Polycystic Ovarian Syndrome (PCOS). This is where the ovaries don’t regularly release an egg due to high ‘male hormones’, called androgens, within the body. Women with PCOS can have either oligomenorrhea or amenorrhea. PCOS presents with additional symptoms, such as excessive hair growth on the face, chest and back, weight gain, and acne. It can be diagnosed if you have these symptoms, and using ultrasound imaging to find cysts on the ovaries.
The menstrual cycle is regulated by hormones produced by the hypothalamus, and if these hormones cease to be produced, this is called hypothalamic amenorrhea. There are a number of reasons why you might stop producing the hormones. One is if you experience excessive weight loss, such as in conditions like anorexia nervosa. Another is excessive exercise, which is why many female athletes and dancers may experience this problem. Stress and long-term illness have also been linked to hypothalamic amenorrhea.
Premature ovarian failure is where the ovary stops producing eggs in a women whose age would suggest she should. It affects approximately 1 in every 20 women before the age of 45. It is known why exactly this happens, but it is thought that the immune system plays a role in attacking the ovaries.
High levels of the hormone prolactin can disrupt the menstrual cycle and cause periods to become irregular or to stop. Prolactin stimulates the production of breast milk and so is normally high after birth, explaining why periods normally stop whilst a mother is breastfeeding. However, when a woman has high levels of prolactin without having given birth, this is abnormal. It can be caused by head injuries, kidney disease, and in rarer cases, a brain tumour secreting prolactin. It can also be a side effect of medications such as calcium channel blockers, omeprazole (proton pump inhibitors), and antidepressants.
The thyroid gland produces hormones which control many body functions, such as metabolism, heart rate and body temperature. If your body produces too much or too little of the thyroid hormones, it can lead to irregular or absent periods.
The last main cause of amenorrhea is genetic conditions, which are present from birth. Turner’s syndrome is rare, affecting 1 in every 2000 girls, where the ovaries fail to produce the hormones necessary for ovulation. Kallmann’s syndrome affects 1 in every 10000 births, and the hormones needed for sexual development are absent. The most rare is androgen insensitivity syndrome, affecting 1 in 20000, where a child is genetically male but their physical characteristics are female.
Due to the wide range of causes, there is not one treatment, there are many for each specific cause. PCOS is usually controlled via regulating the body’s hormones, whilst hypothalamic amenorrhea is mainly treated via lifestyle changes, such as reducing exercise and maintaining a healthy body weight. Unfortunately, there is no treatment for premature ovarian failure. If your periods have become irregular, or stopped completely, you should contact your GP so they can investigate the cause and identify the treatment which will help best.
This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Doctify Limited has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. In the event of an emergency, please call 999 for immediate assistance.