Medically Reviewed by Dr. K on 8 March 2021

What Is Amenorrhea?

Amenorrhea is the absence of menstruation. The two main types of amenorrhea are primary amenorrhea and secondary amenorrhea.


Amenorrhea Types

Primary amenorrhea:

This refers to the absence of menstruation in someone who has not had menstruation by the age of 15.

Secondary amenorrhea:

This refers to the absence of 3 or more consecutive menstruation cycles in a woman who previously have had regular periods.



The main symptom is the absence of menstruation. Alongside this, there may be other accompanying symptoms depending on the underlying cause of disease:

  • pelvic pain
  • headaches
  • acne
  • visual changes
  • hair loss
  • more hair growth, especially on your face
  • milky discharge from nipples
  • absence of breast development (primary amenorrhea)

Causes of Amenorrhea

Amenorrhea can happen for many different reasons. Some cases are natural, whilst others are caused by underlying health conditions.

Natural amenorrhea

Natural amenorrhea occurs during 3 natural life stages in a woman:

  • pregnancy
  • breastfeeding
  • menopause


Some patients on contraceptive medications (oral birth control pills) may not have menstruation. Once stopping their medications, it could take time before regular ovulation and menstruation returns to normal cycles.

Contraceptives that cause amenorrhea included some injectables or implantables, alongside a few intrauterine devices.


Medications can also cause menstruations to stop, they include:

  • chemotherapy for cancer
  • antidepressants
  • antipsychotics
  • some blood pressure medications
  • allergy medications

Lifestyle factors

Certain lifestyle factors can cause amenorrhea:

  • Stress: Mental or physical stress is a major contributing factor to amenorrhea. Stress affects the normal functioning of a part of your brain, the hypothalamus, an area that controls the regulation of hormones responsible for normal menstrual cycles. When the stress that contributes to amenorrhea can be managed well and reduced, regular menstruation can return.
  • Low body weight: Being very underweight, about 10% under a normal healthy weight for your height and age, can adversely affect the regular hormonal functions within your body. This often means the cessation of regular period cycles in women that are very underweight. Once a healthy weight can be achieved, it can take some time before your body adjusts sufficiently to resume regular period cycles.
  • Over-exercise: women who participate in regular overexertion and excessive exercise, which leads to routine high energy expenditure, low body fat and high stress hormones, will suffer from amenorrhea.

Hormonal imbalance

Underlying medical diseases can also contribute to hormonal imbalances that lead to amenorrhea:

  • Polycystic ovary syndrome (PCOS). PCOS causes an imbalance in normal hormonal functioning required to ovulate regularly, leading to absence of menstruation.
  • Thyroid diseases. Overactive thyroid gland (hyperthyroidism) or underactive thyroid gland (hypothyroidism) can affect healthy hormonal pathways contributing to regular menstruation.
  • Pituitary tumor. A benign (non-cancerous) tumor in your pituitary gland can interfere with normal hormonal balance required in healthy menstruation.
  • Premature menopause. Healthy menopause generally occurs around 50 years old in women. However some women experience ovarian failure, in which a large supply of eggs within the ovaries significantly reduces before then, leading to premature menopause.

Structural problems

Reproductive organs in the body can malfunction, leading to amenorrhea:

  • Uterine scarring. Uterine scarring, also known as Asherman’s syndrome, is a condition where scar tissues accumulate within the uterine lining, preventing the normal buildup and shedding of the uterus in a healthy menstrual cycle. This condition can occur after a procedure called dilation and curettage (D&C), caesarean section or uterine fibroid treatment.
  • Absence of reproductive organs. Incomplete or errors in fetal development during pregnancy can lead to absence of defective reproductive organs.
  • Structural defects in reproductive organs. Obstructions or structural defects within the vagina, uterus or fallopian tubes can interfere with normal menstruation cycles.


Amenorrhea Diagnosis

Your doctor will take a full medical history, including family history. A thorough physical and intimate pelvic examination will also need to be carried out.

Women who are sexually active will require a pregnancy test to rule out pregnancy as a cause of amenorrhea.

The following are a list of investigations that may need to be conducted to diagnose the underlying condition causing amenorrhea:

1 Blood Tests: Blood tests to measure hormonal levels pertaining to regular menstrual cycles. Too low or too high levels can interfere with menstruation.

  • follicle-stimulating hormone (FSH)
  • luteinizing hormone (LH)
  • thyroid-stimulating hormone
  • prolactin
  • testosterone
  • dehydroepiandrosterone sulfate (DHEA)

2 Imaging tests for visualisation of organs. These include ultrasound, computerized tomography (CT) imaging and magnetic resonance imaging (MRI).

3 Progestogen hormone challenge test. A test in which progestogen is administered, and upon withdrawal of the hormone, menstrual bleeding should occur. The absence of menstrual bleeding after this test indicates low or lack of oestrogen as a cause of the amenorrhea.

4 Hysteroscopy. A camera will be inserted into the reproductive system to visualise the vagina, cervix, uterus and fallopian tubes.

5 Genetic screening to assess for genetic causes that have caused ovarian failure.

6 Chromosome tests (karyotype test). This looks for chromosomal abnormalities that have caused amenorrhea.


Treatment and outlook

Specific treatment will depend on the underlying cause for the amenorrhea.

For some cases, hormonal therapies or oral contraceptives can restore menstrual cycles. Amenorrhea due to pituitary or thyroid disorders may need treatment with medications. Surgery may be necessary for cases in which there is a structural underlying cause for the amenorrhea.

For cases of stress, low body weight or over exercise; managing stress and ensuring a healthy balanced diet with sufficient levels of activity will enable menstrual cycles to return to normal in time.


Referenced on 2.3.2021:

  1. Hormone Health Network: “Amenorrhea."
  2. National Institute of Child Health & Human Development: “Amenorrhea."
  3. Mayo Clinic: “Amenorrhea.”
  4. Eunice Kennedy Shriver National Institute of Child Health and Human Development: “Amenorrhea.”
  5. Cleveland Clinic: “Amenorrhea.”
  6. Fertility and Sterility: “Menses resumption after cancer treatment-induced amenorrhea occurs early or not at all.”
  7. Children’s Hospital of Philadelphia: “Amenorrhea.”
  8. Yale Medicine: “Amenorrhea.”

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