Missing a period can be worrying, but it does not always mean something is wrong. While pregnancy is one of the most common reasons for a missed period, there are many other possible causes, including stress, significant weight changes, intense physical activity, certain medical conditions and hormonal changes.
Amenorrhoea is the medical term for the absence of menstrual periods. It may occur temporarily or for a longer period and can affect people at different stages of life.
Understanding why periods may stop and knowing when to seek medical advice can help identify underlying health conditions early and ensure appropriate care.
What is Amenorrhoea?
Amenorrhoea means the absence of menstrual periods.
There are two main types:
- Primary Amenorrhoea
Primary amenorrhoea occurs when a person has not had their first period by the age of 15, or within three years of breast development beginning.
Although puberty begins at different ages, delayed menstruation should be assessed by a healthcare professional if these milestones have not been reached.
- Secondary Amenorrhoea
Secondary amenorrhoea occurs when someone who previously had menstrual periods stops having them for:
• three consecutive months if their periods were usually regular; or
• six consecutive months if their periods were usually irregular.Is It Normal to Miss a Period?
Sometimes, yes.
Missing a period can be normal during certain stages of life, including:
• before menstruation begins during puberty;
• during pregnancy;
• while breastfeeding (for some people);
• during the transition to menopause (perimenopause); and
• after menopause.Outside these situations, absent periods should be discussed with a healthcare professional.
What Causes Amenorrhoea?
Amenorrhoea has many possible causes.
- Pregnancy
Pregnancy is the most common cause of missed periods in people who are sexually active.
If you have missed a period and there is any possibility that you could be pregnant, consider taking a pregnancy test and consult a healthcare professional.
- Stress
Physical or emotional stress can temporarily affect the hormones that regulate the menstrual cycle.
Examples include:
• emotional distress;
• illness;
• major life changes; or
• examinations.Periods often return once the underlying cause is addressed.
- Significant Weight Changes
Losing or gaining a large amount of weight within a short period may affect hormone levels and interrupt menstrual cycles.
Very low body weight or inadequate nutrition may also stop ovulation and menstruation.
- Intense Physical Activity
High levels of physical training, particularly when combined with low energy intake, may lead to absent periods.
This is more common in elite athletes but can occur in anyone who exercises intensely.
- Hormonal Conditions
Hormonal disorders can interfere with normal menstrual cycles.
Examples include:
• Polyendocrine Metabolic Ovarian Syndrome (PMOS);
• thyroid disorders;
• elevated prolactin levels; and
• Primary Ovarian Insufficiency (POI).Medicines
Some medicines, including certain hormonal contraceptives and medications used to treat other health conditions, may affect menstruation.
Do not stop taking prescribed medication without medical advice.
Signs and Symptoms
The main symptom is the absence of menstrual periods.
Depending on the cause, other symptoms may include:
• acne;
• excessive facial or body hair;
• headaches;
• vision changes;
• breast discharge unrelated to breastfeeding;
• hot flushes;
• vaginal dryness;
• pelvic pain; or
• unexplained weight changes.How is Amenorrhoea Diagnosed?
A healthcare professional may:
• ask about your menstrual history;
• discuss your medical history;
• ask about lifestyle, diet and exercise;
• perform a physical examination;
• recommend a pregnancy test where appropriate;
• request blood tests to assess hormone levels; and
• arrange an ultrasound or other imaging tests if needed.Diagnosis aims to identify the underlying cause rather than simply confirming that periods have stopped.
Treatment
Treatment depends on the underlying cause.
Possible treatments include:
• managing stress;
• improving nutrition;
• achieving or maintaining a healthy weight;
• adjusting exercise routines where appropriate;
• treating hormonal conditions;
• changing medications if advised by a healthcare professional; or
• treating any underlying medical condition.Many people resume normal menstrual cycles once the cause has been addressed.
Possible Complications
If left untreated, some causes of amenorrhoea may increase the risk of:
• infertility;
• reduced bone strength (osteoporosis);
• complications related to untreated hormonal disorders; and
• reduced quality of life.Early assessment helps reduce these risks.
When Should You See a Healthcare Professional?
Seek medical advice if:
• you have not had your first period by 15 years of age;
• your periods stop for three months or longer and you are not pregnant;
• your periods become suddenly irregular after previously being regular;
• you have pelvic pain together with absent periods;
• you have breast discharge unrelated to breastfeeding;
• you experience severe headaches or vision changes; or
• you think you may be pregnant.Myths and Facts
Myth: Missing one period always means you are pregnant.
Fact: Pregnancy is one possible cause, but stress, illness, hormonal conditions and many other factors can also cause missed periods.
Myth: It is normal for periods to disappear because of stress forever.
Fact: While stress can temporarily affect the menstrual cycle, persistent absent periods should be assessed by a healthcare professional.
Myth: If you are not menstruating, you do not need medical attention.
Fact: Amenorrhoea may be a sign of an underlying health condition that requires treatment.
Myth: Missing periods is harmless.
Fact: Some causes of amenorrhoea can affect fertility, bone health and overall wellbeing if left untreated.
Frequently Asked Questions
- Is it normal to miss one period?
Sometimes. Stress, illness or hormonal changes can occasionally delay a period. However, if there is a possibility of pregnancy, take a pregnancy test. If your periods remain absent or repeatedly become irregular, consult a healthcare professional.
- Can stress stop my period?
Yes. Physical or emotional stress can temporarily affect the hormones that regulate menstruation.
- Can exercise stop my period?
Yes. Very intense exercise, particularly when combined with inadequate nutrition, may cause periods to stop.
- Should I worry if my period is late?
A late period is not always a cause for concern. However, if you miss several periods, have other concerning symptoms or think you may be pregnant, seek medical advice.
Key Messages
• Amenorrhoea is the medical term for absent menstrual periods.
• Pregnancy is a common cause of missed periods, but many other medical and lifestyle factors can also affect the menstrual cycle.
• Missing a period is normal during puberty, pregnancy, breastfeeding and after menopause.
• Persistent absent periods should always be assessed to identify the underlying cause.
• Early diagnosis and treatment can help protect fertility, bone health and overall wellbeing.Related Articles
• Understanding the Menstrual Cycle
• Irregular Periods
• Polyendocrine Metabolic Ovarian Syndrome (PMOS)
• Primary Ovarian Insufficiency (POI) (coming soon)
• Menopause and Perimenopause (coming soon)Knowledge Hub Series: Period Talk Uganda – Evidence-Based Menstrual Health Resources