Introduction

When you don’t have a period for three months or more, and you’ve received a period before, it is classified as secondary amenorrhea. Secondary amenorrhea can be caused by many things, it is not something to be taken lightly.

It is essential to know the cause of secondary amenorrhea. Your menstrual cycle is intimately connected to your health. If you notice disruptors, it could mean there’s something wrong regarding hormones, nutrition, stress or illness.

If you’ve never had your period at all and you’re 15, then you have primary amenorrhea which is not the same as secondary amenorrhea. There might be some overlapping issues that are the same, however, you should consult a professional doctor instead.

Physiological Causes

Not all missed periods are serious and alarming, there are some biological processes that are completely normal for the human body.

Pregnancy

By far the most common and well-known cause, pregnancy stops the menstrual cycle to support the developing fetus. A missed period is often the first noticeable sign, and in cases of secondary amenorrhea, it’s always the first possibility to rule out.

Breastfeeding

If you are currently breastfeeding, you might have lactational amenorrhea. Lactation suppresses the hormones and temporarily pauses your menstruation while breastfeeding, especially in the first few months after childbirth.

Perimenopause and Menopause

When people reach a certain age, they enter a transitional phase: Perimenopause (40s or earlier). Eventually leading up to menopause (12 consecutive months without a period). This is completely normal and natural, so if you fall into the age range, you should not worry.

Hormonal Imbalances

Your reproductive symptom is mainly run by your hormones, if your hormones are imbalanced, your period would be irregular.

Polycystic Ovary Syndrome (PCOS)

PCOS is a common cause for missed periods. How PCOS makes your period abnormal is due to an abundance of androgens (male hormones), insulin resistance, or both. Some symptoms are abnormal periods, acne, weight gain, or excess hair growth. 

Thyroid Disorders (Hypothyroidism and Hyperthyroidism)

A small gland in the neck called your “thyroid” plays an important role in regulating metabolism and menstrual health. Hypothyroidism (underactive thyroid) can cause heavy, infrequent, or absent periods, while hyperthyroidism (overactive thyroid) can shorten or halt cycles altogether. In both cases, menstrual changes are often one of the first signs something’s off.

Pituitary Disorders

The role of pituitary gland is to send hormonal signals to other parts of the body. Having a functioning pituitary gland is essential for hormonal balance, and without it, your period would be irregular, or even completely stop.

Lifestyle and Environmental Triggers

Low Body Weight / Rapid Weight Loss

Being significantly underweight (typically less than 85% of ideal body weight) or losing weight too quickly can stop ovulation. Low energy availability will turn on survival mode and redirect energy away from reproduction. This is a common trigger in individuals with eating disorders or intense dieting habits.

Obesity or Sudden Weight Gain

On the other hand, excess body fat could also disrupt the balance of estrogen and insulin, both critical to menstrual regulation. Obesity is also closely linked to PCOS, compounding the effects on ovulation.

Excessive Exercise (Especially in Athletes)

Constantly doing rigorous and high intense actives will cause your body to go into an energy deficit. Your body experiences physical stress by suppressing reproductive hormones, leading to an absence in mensural cycle.

Severe Stress (Emotional or Physical)

Major emotional trauma, chronic anxiety, or physical stress (like illness or injury) can interfere with the brain’s hormonal signals. The hypothalamus (your body’s control center) can pause ovulation as part of a broader stress response.

Eating Disorders (Anorexia Nervosa, Bulimia)

Disordered eating will have tremendous effects on the body’s endocrine system. It basically encompasses all of the issues mentioned above (undereating, high level exercise, high level of stress). The body doesn’t receive enough energy to sustain the reproductive organ.

Medications and Medical Treatments

Hormonal Contraceptives

Birth control methods (pills, IUDs, implants, and injections) can alter your hormone levels, preventing ovulation. These medication affects your hormones and changes the chemistry in your body. Therefore, in some cases, some people would receive their period once again after they stop taking these. However, for others, it might take longer for your hormones to function normally without these contraceptives.

Other Medications

Several drugs can disrupt menstrual cycles as a side effect. Check the drug’s description and labels on the bottle. Make sure to read everything listed!!

Summary Table: Quick Look at Common Triggers of Secondary Amenorrhea

Category	Examples
Physiological	Pregnancy, breastfeeding, menopause
Hormonal	PCOS, thyroid disorders, pituitary issues
Lifestyle	Weight loss/gain, excessive exercise, stress
Medications	Hormonal contraceptives

When to See a Doctor

You should visit a doctor when…

• Your periods have stopped for three months or more without an obvious cause.
  
• You experience other symptoms such as severe headaches, vision changes, excessive hair growth, or pelvic pain.
  
• You have a history of eating disorders, significant weight changes, or intense exercise.
  
• You’re concerned about fertility or long-term health impacts.
  

It is extremely important to get professional help to pinpoint the exact problem you need to fix. The earlier you discover the reason, the higher chance future health concerns such as infertility and bone loss will be prevented.

Resources for Further Reading

If you want more research on this topic, check out these links I’ve pasted below:

• Mayo Clinic: Amenorrhea – Symptoms and causes
  
• American College of Obstetricians and Gynecologists (ACOG): Amenorrhea: Absence of Periods
  
• MedlinePlus: Absent menstrual periods – secondary
  
• Cleveland Clinic: Amenorrhea: Types, Causes, Symptoms, Diagnosis & Treatment
  
• WebMD: Amenorrhea: Causes, Symptoms, & Treatment
  

My experience

I overcame it after losing my period for over 3 years due to overexercising and undereating (Learn more). I know the journey is rough, but keep pushing through! It’ll be worth it!

If you have any questions or concerns you can leave a comment below! Don’t forget to subscribe to upcoming posts on recovery, wellness, and finding balance.