Bleeding Between Periods: Causes, Warning Signs, and When to See a Doctor

Bleeding between periods—also called intermenstrual bleeding, spotting, or metrorrhagia—can happen for several reasons. In many cases, occasional spotting is related to temporary hormonal changes, birth control adjustments, or perimenopause.

However, persistent or unusual bleeding outside of your normal menstrual cycle can sometimes signal an underlying health condition. If spotting between periods occurs frequently, becomes heavy, or is accompanied by other symptoms, it’s important to speak with a healthcare provider.

Below are three potentially serious causes of bleeding between periods, along with warning signs that may require medical attention.

1. Hormonal Imbalance

Hormones regulate the menstrual cycle. Estrogen stimulates growth of the uterine lining, while progesterone prepares the uterus for pregnancy. When these hormones become imbalanced, the menstrual cycle can be disrupted and lead to spotting between periods.

Common causes of hormonal imbalance include:

• Polycystic ovary syndrome (PCOS)
• Thyroid disorders
• Perimenopause or menopause
• Starting or changing birth control

Hormonal imbalances may also contribute to symptoms such as:

• Irregular menstrual cycles
• Mood changes or anxiety
• Weight fluctuations
• Fatigue
• Difficulty ovulating

If irregular bleeding persists, a healthcare provider may recommend hormone testing or a thyroid panel to determine the underlying cause.

2. Infection

Bleeding between periods may also occur due to vaginal or pelvic infections. These infections can irritate the reproductive tract and cause inflammation or abnormal bleeding.

Common infections linked to spotting include:

• Yeast infections
• Bacterial vaginosis
• Sexually transmitted infections (STIs) such as chlamydia or gonorrhea

If untreated, certain infections may lead to pelvic inflammatory disease (PID), which can cause:

• Chronic pelvic pain
• Scarring in the fallopian tubes
• Fertility problems

Symptoms that may indicate infection include:

• Unusual vaginal discharge
• Vaginal itching or odor
• Pain during intercourse
• Pelvic discomfort

If these symptoms occur along with spotting, testing and treatment should not be delayed.

3. Reproductive Cancers

Although less common, bleeding between periods can sometimes be an early symptom of reproductive cancers, including:

• Cervical cancer
• Uterine (endometrial) cancer
• Ovarian cancer
• Vaginal cancer

Early detection is critical because treatment outcomes are significantly better when cancers are diagnosed early.

Warning signs that should be evaluated promptly include:

• Pelvic pain
• Pain during intercourse
• Unexplained weight loss
• Persistent bloating
• Abnormal discharge

If spotting occurs frequently or appears after menopause, a medical evaluation is strongly recommended.

Can Diabetes Affect Menstrual Bleeding?

Women with type 2 diabetes, particularly those with insulin resistance, may experience hormonal changes that disrupt normal ovulation. This can lead to irregular menstrual cycles and bleeding between periods.

Type 2 diabetes is also associated with an increased risk of uterine (endometrial) cancer and early menopause. Managing blood sugar levels and maintaining regular medical checkups can help reduce these risks.

Other Possible Causes of Spotting Between Periods

Not all cases of intermenstrual bleeding are serious. Other possible causes include:

• Uterine fibroids
• Perimenopause
• Ovulation spotting
• Stress or major lifestyle changes
• Injury or irritation from tampons, intercourse, or medical devices

While occasional spotting may be harmless, persistent or unexplained bleeding should be evaluated by a healthcare professional.

When to Seek Emergency Care

Most cases of spotting are not emergencies, but certain symptoms require immediate medical attention.

Seek urgent care if bleeding between periods occurs with:

• Severe pelvic pain
• Fever or signs of infection
• Dizziness or fainting
• Heavy bleeding
• Bleeding during pregnancy

Listening to your body and seeking medical care when something feels unusual can help detect serious conditions early.

Talk to a Doctor About Irregular Bleeding

At BASS Medical Group, our team of primary care physicians, OB-GYN specialists, and women’s health providers can help identify the cause of abnormal bleeding and recommend the appropriate treatment.

If you are experiencing bleeding between periods, irregular cycles, or unexplained spotting, scheduling a medical evaluation can help protect your long-term health.