While a missed menstrual period is the hallmark of early pregnancy, missing a period can be due to a number of factors and conditions. The term amenorrhea is used by doctors to describe the absence of menstruation. Primary amenorrhea (in which a woman does not begin menstruating) is very rare, while secondary amenorrhea (absence of periods in a previously menstruating woman) is much more common. Periods may also be irregular, with skipped periods, for the first few years after a woman has begun menstruating and in the perimenopause (the time period preceding menopause).
A woman is not considered to have secondary amenorrhea until she has missed three menstrual periods in a row. However, the causes of secondary amenorrhea are generally the same factors or conditions that can lead to a skipped period. If a woman is not pregnant, a missed menstrual period may be due to a wide variety of both physical and emotional conditions that range from lifestyle stress to rare and serious diseases. Many of the conditions that underlie missed menstrual periods interfere with the body's hormonal balance, particularly regarding levels of the sex hormones.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.
Main Article on Missed Menstrual Period
Pictures, Images, Illustrations & Quizzes
Am I Pregnant? Test Your Early Pregnancy IQ
What are early pregnancy symptoms? In some women, symptoms range from a missed period to feeling lightheaded. Others may...
Early Signs & Symptoms of Pregnancy
Read about early signs and symptoms of pregnancy such as nausea and vomiting (morning sickness), bloating, tender breasts, and...
Menopause & Perimenopause: Symptoms, Signs
What is menopause? What are the signs of menopause? What age does menopause start? Learn about menopause and perimenopause...
Menopause Quiz: Symptoms & Signs
The Menopause Quiz challenges your knowledge about the time in a woman’s life when menstruation ceases. Menopause can bring many...
Causes of Missed Menstrual Period
Anorexia is an eating disorder characterized by markedly reduced appetite or total aversion to food. Anorexia is a serious...
Brain Tumor (Symptoms, Signs, Types, Causes, Survival Rates)
A brain tumor can be either non-cancerous (benign) or cancerous (malignant), primary, or secondary. Common symptoms of a primary...
People with bulimia nervosa, an eating disorder that involves episodes of bingeing and purging, experience symptoms and signs...
Early Pregnancy Symptoms and Signs
Pregnancy symptoms can vary from woman to woman, and not all women experience the same symptoms. When women do experience...
Ectopic Pregnancy (Tubal Pregnancy)
An ectopic pregnancy is a pregnancy located outside the inner lining of the uterus. The majority of ectopic pregnancies occur in...
Menopause is the time in a woman's life when menstrual periods permanently stop, also called the "change of life." Menopause...
Obesity is the state of being well above one's normal weight. A person has traditionally been considered to be obese if they are...
PMS vs. Pregnancy (Differences and Similarities)
Many women have difficulty figuring out if they are pregnant, have PMS, or are about to start their period. The most common signs...
Polycystic Ovarian Syndrome (PCOS)
Polycystic ovarian syndrome (PCOS), also known by the name Stein-Leventhal syndrome, is a hormonal problem that causes women to...
Pregnancy (Week By Week, Trimesters)
Signs and symptoms of pregnancy vary by stage (trimester). The earliest pregnancy symptom is typically a missed period, but...
Primary Ovarian Insufficiency (POF, Premature Ovarian Failure, POI)
Primary ovarian iInsufficiency (POF, Premature Ovarian Failure, POI) is the cessation of normal functioning of the ovaries in...
Prolactinoma (Pituitary Tumor)
Prolactinoma is an adenoma (benign tumor) of the pituitary gland. Causes of many prolactinomas are unknown. Symptoms in women...
Stress occurs when forces from the outside world impinge on the individual. Stress is a normal part of life. However,...
Normal vaginal bleeding (menorrhea) occurs through the process of menstruation. Abnormal vaginal bleeding in women who are...