What Causes Irregular Vaginal Bleeding?

November 6, 2017
What causes irregular vaginal bleeding? Learn about all of the possible causes and how it can be treated in this article.

If you notice irregular vaginal bleeding, it’s a good idea to go to your gynecologist.  You need testing to determine the cause, and to rule out any possible complications

Bleeding that occurs in the middle of your menstrual cycle is known as intermenstrual bleeding or metrorrhagia.

It’s characterized by the presence of blood outside of the days that correspond to your normal days of menstruation.

Metrorrhagia can be due to several different factors and many people think it’s caused by irregular menstrual cycles, but it’s not.

Bleeding between your periods is a sign that something is wrong, so it’s important to identify the cause and avoid any complications.

If you have fairly regular periods and have ever experienced this phenomenon, don’t be alarmed – just try to identify the cause that triggered the bleeding.

If it’s happening to you and you don’t know why today we want to tell you about the main causes of bleeding outside of your normal menstrual cycle.

Causes of bleeding between periods

There are many causes that can lead to this symptom. Gynecologists divide them into three main classes, however:

  • Vaginal
  • Uterine
  • Ovarian

Because bleeding can originate from any of these three locations, your condition may be due to several reasons.

Also see: 6 reasons your period is irregular



Contraceptive pills and contraceptive devices such as intrauterine devices (IUDs) in particular can cause irregular bleeding.

This could be due to the level of hormones contained in the pills or, in the case of an IUD, a problem with its placement in the uterus.

If you’ve started a new contraceptive treatment and this is happening to you, talk with your gynecologist. He will evaluate your situation and potentially try a different option to avoid this problem.

Remember that any contraceptive treatment tends to alter your menstrual cycle somewhat. So you may experience episodes of very heavy flow, or the opposite, very light periods.

Hormonal problems

A woman’s body produces two main hormones (estrogen and progesterone) that are responsible for regulating her menstrual cycle.

When there’s an imbalance between the two, irregular bleeding can occur either during the period or any other days in the cycle.

This can lead to very painful periods, very heavy flow, or bleeding between periods.

Such imbalances can be caused by:

Sexually transmitted diseases (STDs)


STDs, especially gonorrhea and chlamydia, may cause symptoms of irregular vaginal bleeding after having unprotected sex.

Some of the symptoms of STDs include:

  • Fever
  • Burning or pain when urinating
  • Pain during intercourse
  • Unusual vaginal discharge

All of these may coincide with bleeding in the middle of your menstrual cycle.

If you experience any of these symptoms, it’s very important that you immediately consult your doctor.  An exam should rule out any possible complications and get proper treatment.


This is one of the most common causes of irregular vaginal bleeding and can affect either your vagina or your urinary tract.

Inflammation and irritation can cause irregular bleeding when you have an infection, but it’s typically very mild.

You can contract an infection through:

  • Poor hygiene
  • Uncontrolled hormone levels
  • Sexually transmitted diseases
  • Vaginal douches


During what’s known as peri-menopause, irregular bleeding can also occur. This is when you experience light spotting or very light bleeding in the middle of going through menopause.

Even when your regular periods have stopped and your ovaries are no longer active, some women still have a small amount of brownish discharge, similar to blood.

Visit this article: 5 things you should do to care for your skin during menopause

Polyps in the uterus


These growths that originate in the uterus can cause irregular vaginal bleeding. Many women won’t notice any changes or will experience a different symptom.

The presence of blood or abdominal cramping may be a sign that something is happening with your uterus.


They are non-cancerous tumors that form inside the uterus and can be detected by a gynecologist.

Some clear symptoms include:

Ovarian cysts

These are generated in the ovaries and rupture after the release of the ovum. This rupture causes cramping, abdominal pain, and vaginal bleeding.

Cysts are the most common cause of bleeding between periods.

When you see the first symptoms of irregular bleeding, we recommend that you see your gynecologist. They will evaluate your condition and potentially help you avoid a more serious health problem.

Skelton, A. K. (2016). Menstrual disorders. In Family Medicine: Principles and Practice. https://doi.org/10.1007/978-3-319-04414-9_110