--- title: "What causes irregular periods?" date: 2025-09-09 author: "HSFC Kenya" featured_image: "https://hsfckenya.com/wp-content/uploads/2026/07/What-causes-irregular-periods.png.webp" categories: - name: "Female Fertility" url: "/resource-library/articles/category/female-fertility.md" - name: "Female Infertility" url: "/resource-library/articles/category/female-infertility.md" - name: "Treatments and Services" url: "/resource-library/articles/category/treatments-and-services.md" --- # What causes irregular periods? Irregular periods can be caused by a variety of factors, primarily related to hormonal fluctuations. Common causes include hormonal birth control, Polycystic Ovary Syndrome (PCOS), stress, and [weight](https://hsfckenya.com/resource-library/articles/infertility/infertility-risk-factors-diagnosis-and-treatments/) changes. Other potential causes include thyroid issues, certain medications, and underlying medical conditions. ###### **OVERVIEW OF ABNORMAL MENSTRUATION** A normal menstrual cycle typically spans 21–35 days, with bleeding lasting 4–7 days; the average cycle is about 29 days. Menstruation is considered irregular if it involves: - Cycles shorter than 21 days or longer than 35 days - Missing three or more consecutive periods - Bleeding that’s unusually light or heavy, prolonged, or accompanied by severe symptoms like pain or nausea - Bleeding between cycles, after intercourse, or after menopause ###### **COMMON FORMS OF ABNORMAL BLEEDING** - **Amenorrhea:** No periods for 90+ days (excluding pregnancy, breastfeeding, or menopause); or delayed onset by age 15–16 - **Oligomenorrhea:** Infrequent periods fewer than 6–8 annually, or cycles longer than 35 days - **Dysmenorrhea:** Painful periods and severe cramping - **Menorrhagia:** Excessively heavy or long periods, often soaking through pads/tampons every hour - **Menometrorrhagia** *(Abnormal Uterine Bleeding)***:** Bleeding that’s irregular, prolonged, heavy, or occurs between regular cycles ###### **UNDERLYING CAUSES** **HORMONAL IMBALANCES:** Such as[ PCOS](https://hsfckenya.com/resource-library/articles/female-fertility/understanding-the-role-of-hormones-in-pcos/), thyroid disorders and perimenopause. - **Normal Fluctuations:** In teenagers and women approaching menopause, periods can naturally become irregular due to fluctuating hormone levels. - **Birth Control:** Hormonal birth control, like pills or IUDs, can affect the menstrual cycle, leading to irregular bleeding patterns. - **PCOS:** This hormonal disorder is a common cause of irregular periods, often accompanied by other symptoms like acne and excessive hair growth. - **Thyroid Problems:** Both an overactive (hyperthyroidism) or underactive (hypothyroidism) thyroid can disrupt the menstrual cycle. **LIFESTYLE FACTORS:** Lifestyle factors such as stress, weight changes, low body fat, and illness. - **Stress:** High stress levels can impact hormone regulation, leading to irregular periods. - **Weight Changes:** Significant weight gain or loss can disrupt hormonal balance, affecting the menstrual cycle. - **Excessive Exercise:** Intense physical activity can also lead to hormonal imbalances, potentially causing irregular periods or even missed periods. **OTHER MEDICAL CONDITIONS:** Reproductive system conditions such as fibroids, polyps, endometriosis and PID. Other medical issues such as bleeding/clotting disorders, liver/kidney diseases. Tumours or cancer such as uterine or ovarian. Medications such as blood thinners and hormone therapy. - **Infections:** Infections like [Pelvic Inflammatory Disease](https://hsfckenya.com/resource-library/articles/treatments-and-services/sexually-transmitted-disease-std-and-infertility/) (PID) can cause inflammation and scarring in the reproductive organs, leading to irregular periods. - **Certain Medications:** Some medications, including chemotherapy drugs and some antidepressants, can have side effects that affect the menstrual cycle. - **Underlying Medical Conditions:** Conditions like [endometriosis](https://hsfckenya.com/resource-library/articles/treatments-and-services/endometriosis-and-fertility/), fibroids, and certain cancers can also cause irregular periods. **PREGNANCY AND BREASTFEEDING:** - **Pregnancy:** Missed periods are a common sign of pregnancy, and even early pregnancy can sometimes cause irregular bleeding. - **Breastfeeding:** Periods may be absent or irregular while breastfeeding, especially when breastfeeding exclusively. ###### **DIAGNOSIS & TREATMENT** - Keep a menstrual diary of cycle length, flow, and symptoms. - Healthcare providers typically conduct physical exams, including a pelvic exam, and may order blood tests (hormones, anemia, clotting), imaging (ultrasound, sonohysterogram), Pap smear, biopsy, or hysteroscopy. - Treatments vary by cause and may include: **Medications:** Hormonal contraception, nonsteroidal anti-inflammatory drugs, tranexamic acid, GnRH therapies, iron supplements **Procedures:** Hysteroscopy, dilatation and curetting (D&C), fibroid removal, uterine artery embolisation, ablation, or hysterectomy in severe cases ###### **OUTLOOK & WHEN TO SEEK HELP** Chronic irregular bleeding can lead to anemia and negatively impact quality of life, but most cases are treatable once the underlying cause is identified. Seek medical attention if: - Bleeding disrupts daily activities, or blood loss is heavy enough to risk anemia - Periods are highly unpredictable, excessively heavy, or include bleeding outside the normal cycle Read more about how to interpret and manage irregular periods in this [blog](https://my.clevelandclinic.org/health/diseases/14633-abnormal-menstruation-periods) by the Cleveland Clinic. If you are concerned about irregular periods, it’s always best to consult with a healthcare professional for proper diagnosis and treatment. If you have been on the journey to get pregnant and it has not worked out for over a year, or at least 6 months for women 35 years and over, book an appointment with us at Harley Street Fertility Centre for a consultation with one of our Fertility Specialists. ![](https://hsfckenya.com/wp-content/uploads/2025/09/What-causes-irregular-Period.jpg)