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Abnormal Uterine Bleeding: Spotting, Bleeding Between Periods and After Sex

What is abnormal uterine bleeding?

Abnormal uterine bleeding (AUB) means bleeding from the uterus that is different from your normal pattern in frequency, regularity, duration, or amount. Examples include:

• Spotting or bleeding between periods
• Bleeding after sex
• Periods that are much heavier or longer than usual
• Periods that come more often than every 24 days or less often than every 38 days
• Any vaginal bleeding after menopause (12 months after the last period)

What causes abnormal uterine bleeding?

Doctors use the PALM-COEIN system to group causes:

•  Structural (PALM): polyps of the uterus or cervix, adenomyosis, fibroids (leiomyomas), and malignancy or precancerous changes (hyperplasia)
• Non-structural (COEIN): coagulation (bleeding) disorders, ovulatory problems such as PCOS or perimenopause, endometrial causes, iatrogenic causes such as hormonal contraception or blood thinners, and causes not yet classified

Other common causes include pregnancy-related bleeding, infections such as chlamydia or cervicitis, cervical polyps, and missed or newly started birth control pills.

What symptoms can occur with abnormal bleeding?

Bleeding may be the only symptom. Some people also have pelvic pain, unusual discharge, pain during sex, or tiredness from anemia.

When should I see a doctor?

Book a visit for any bleeding between periods, bleeding after sex, a change in your usual bleeding pattern that lasts more than 2 to 3 cycles, or any bleeding after menopause. Bleeding after menopause should always be evaluated, even if it is only a small amount.

Seek emergency care (call 119) if you have:

• Very heavy bleeding that soaks a pad every hour for 2 hours or more
• Dizziness, fainting, or a racing heartbeat
• Bleeding with severe abdominal pain
• Bleeding with a positive pregnancy test, which can be a sign of miscarriage or ectopic pregnancy

How is abnormal bleeding evaluated at the clinic?

• A pregnancy test for anyone who could be pregnant
• A speculum exam to check the cervix for polyps, inflammation, or other changes
• A Pap smear and HPV test if cervical screening is due, especially for bleeding after sex
• Tests for infections such as chlamydia and gonorrhea when indicated
• A transvaginal ultrasound to check the uterine lining, fibroids, polyps, and ovaries
• Blood tests for anemia, hormones, or thyroid function

If the uterine lining is thick, or if bleeding occurs after menopause, a sample of the lining (endometrial biopsy) or hysteroscopy may be recommended. The doctor will explain these steps and refer you to a hospital when needed.

What are the treatment options?

Treatment depends on the cause:

• Hormonal treatment, such as birth control pills, progestin, or a hormonal IUD, for bleeding related to ovulation
• Tranexamic acid or NSAIDs to reduce heavy bleeding
• Antibiotics for infections
• Removal of a cervical polyp, which is often a simple procedure; uterine polyps and fibroids may need hysteroscopic surgery at a hospital by referral
• Iron for anemia

Individual results vary.

Getting care in English near Seongsu Station

Eunice Women's Clinic is on the 8th floor of Bethel Place, 120 Achasan-ro, Seongdong-gu, Seoul. The building is across the crosswalk from Seoul Subway Line 2 Seongsu Station Exit 3, about a 1-minute walk ( directions). Dr. Eun Mi-na, a female board-certified OB-GYN, holds consultations about abnormal bleeding in English.

   

Day	Hours
Mon, Wed, Fri	10:00–19:00 (lunch 13:30–14:30)
Tue, Thu	10:00–20:00 (lunch 13:30–14:30)
Sat	10:00–14:00 (no lunch break)
Sun and public holidays	Closed

Booking is recommended. You can book through Naver Booking, the KakaoTalk channel (search "유니스산부인과"), or by phone at +82-2-467-3100 ( how to book). Call or message to check same-day availability.

Frequently asked questions

Is spotting between periods serious?

Spotting between periods is often harmless, for example around ovulation or when starting birth control pills. However, it can also be caused by infection, polyps, or cervical changes. If it happens repeatedly or after sex, see a gynecologist.

Why do I bleed after sex?

Bleeding after sex can be caused by cervical inflammation, infection such as chlamydia, cervical polyps, vaginal dryness, or, less often, cervical changes that need further tests. A speculum exam and cervical screening help find the cause.

Is bleeding after menopause normal?

No. Any vaginal bleeding 12 months or more after your last period should be checked by a doctor. Most causes are benign, such as thin vaginal tissue, but the uterine lining needs to be evaluated to rule out precancer or cancer.

Can birth control pills cause spotting?

Yes. Breakthrough spotting is common in the first 3 months of starting pills or after missing pills. If spotting continues beyond 3 months, or if you have missed pills and had sex, see a doctor and consider a pregnancy test.

What should I bring to my appointment?

Bring the dates of your recent periods and bleeding episodes, a list of medicines and contraceptives you use, and results of any previous Pap smears or ultrasounds. A period-tracking app can be very helpful.

Related pages

•  Transvaginal Ultrasound
• Pap Smear
• Heavy Periods
• Cervical Polyps
• Irregular Periods

This page provides general health information for patients and does not replace a consultation with a doctor. Individual results vary. If you have severe pain, heavy bleeding, fainting or other urgent symptoms, call 119 or go to the nearest emergency room. Page updated September 2026.