What Causes Back Pain and Vaginal Discharge?

Key takeaways:

• A vaginal discharge may occur with or without back pain.
• When there is a link between back pain and vaginal discharge, it usually indicates a more serious problem than either symptom alone.
• The internal pelvis (pelvic cavity) connects the vagina with the inside of your body (your back and its perception of pain).

Two of the most common ailments are back pain and vaginal discharge (also known as leukorrhea). If they occur at the same time, they may have separate causes and be unrelated – but that isn’t always the case. Sometimes the two symptoms are linked. The back pain and vaginal discharge may either be caused by the same problem or by one of the symptoms aggravating the other.

A vaginal discharge may be normal and harmless. But it can also be a warning sign of an infection – possibly a serious one. Back pain also varies in severity. It may be due to an orthopedic problem, such as a herniated disk; a neurological problem (e.g., a pinched nerve); or a musculoskeletal problem like muscle strain.

When back pain and a vaginal discharge occur together, this is a hybrid (combination) medical issue. Thus, an accurate diagnosis becomes more difficult. Pelvic conditions, for instance, can cause inflammation that radiates pain along the same nerves the back uses. Indeed, it can be challenging for healthcare providers to tell what, exactly, is happening.

Are lower back pain and vaginal discharge typically related?

The only body part that can link back pain to a vaginal discharge is the pelvis, which is the lower part of the abdomen. The pelvis is the cavity that’s exposed to the outside world via the vagina. It also houses support ligaments of pelvic organs that attach to the back’s internal musculoskeletal system of ligaments.

The vagina:

• Its opening is protected by skin folds called the labia minora; sexual contact and even poor personal hygiene can allow sperm, bacteria, and other microscopic organisms to get in;
• Communicates with the internal body via continuity with the cervix (and on to the uterus and fallopian tubes); this establishes a route into the internal body from the outside.

The pelvis:

• Is bordered by the bladder and rectum in the front, and the spine and back muscles in the back;
• Houses the uterus, tubes, ovaries, and intestinal and colon structures;
• Is covered by a thin, filmy layer of tissue, rich in pain nerves, called the peritoneum.

Common causes of upper, lower, or middle back pain and vaginal discharge

We’re referring to pathological vaginal discharge here, meaning discharge caused by infections. These can be secondary to:

• Yeast (fungal) infection
• Trichomonas vaginalis, a sexually transmitted infection (STI)
• Bacterial vaginosis, a vaginal infection caused by an imbalance of bacteria in the vagina;
• STIs from bacteria (gonorrhea, chlamydia, etc.)

The body is very good at keeping the first three isolated in the vagina – but STDs are different. They are invasive and virulent enough to infect tissues higher up, which spills inflammatory cells into the pelvis. Since the entire pelvis is covered in the pain nerve-rich peritoneum, any area it covers can become inflamed.

Crosstalk

This potential reaction in the peritoneum is known as inflammatory “crosstalk.” It refers to pain passing to and from the reproductive organs, bladder, rectum and colon, kidneys, and structures of the back (ligaments). It can even affect the diaphragm, which plays a role in upper back pain.

Infections/STDs

Gonorrhea is the STD most likely to cause a noticeable vaginal discharge. Chlamydia can also cause a discharge, but often has no symptoms until the onset of back pain.

Pain signals can travel along your pelvic nerves and seem painful locally (limited to your pelvis). These signals, however, may reach farther to the spinal nerves. There, they mix with signals coming from your back, making it feel like your back is hurting. This is called “referred pain.” Back pain with a vaginal discharge is not from the discharge, but part of the same process of inflammation that causes both.

Pelvic infection only: lower back pain with vaginal discharge

Sometimes the spread of inflammation is limited to just the uterus. When that happens, the ligaments anchoring the uterus to your sacrum can cause lower back pain.

Kidney involvement: middle back and/or flank pain with vaginal discharge

If the inflammation involves the peritoneum (covering your kidneys), this can cause pain to your middle back and even your sides.

Abdominal involvement: upper back pain with vaginal discharge

The pelvis is located below the abdomen. Although it is considered separate from the abdomen, it is continuous with it. This distinction helps explain the causes of upper back pain associated with conditions that also cause a vaginal discharge (infection). If the inflammation travels as high as your diaphragm, this can cause pain in the upper back.

What back pain and vaginal discharge can mean based on menstrual cycles or pregnancy

The pelvis is a very busy place. This is true anatomically, as well as physiologically. The different phases of the menstrual cycle or pregnancy create entirely different physiologies. This, in turn, makes back pain and vaginal discharge different in each.

If you are not pregnant

The menstrual cycle begins with a rise in estrogen. During mid-cycle, ovulation leads to a rise in progesterone. If an egg isn’t fertilized (i.e., pregnancy doesn’t occur), there is a sharp decline in progesterone levels. The result is a menstrual period, which is the body’s shedding of the uterine lining.

Of these phases, vaginal discharge from yeast is more likely during the estrogen-rich first half. While bacterial vaginosis and even trichomonas can occur anytime, bacterial infections are more likely to begin during your period. That’s because the debris provides a rich environment to support bacterial growth. Bacterial infection can become invasive beyond the vagina – moving into the pelvis. This provokes the inflammation that causes back pain.

If you recently missed your period or are unsure if you’re pregnant

A late period may be just that … late. During this time, you may have an extended second half of your cycle with high progesterone. Or, it may be that you’re pregnant, and both estrogen and progesterone are rising. Any of these can alter how a vaginal discharge is perceived or how your body defends against an infection that causes one.

Back pain, however, is never normal. In these cases, the vaginal discharge is secondary – but addressing the cause of the back pain will also include addressing the discharge.

If you’re in your first trimester of pregnancy

As your uterus begins to expand, the ligaments anchoring it in place can be stretched. That causes pain in various points in the lower back. The result? Lower back pain with or without the physiological discharge of pregnancy.

A bloody vaginal discharge in the first trimester can indicate:

• A yeast or other vaginal infection
• A more serious infection with or without back pain
• An ectopic pregnancy (also known as a tubal pregnancy) with or without back pain. A ruptured ectopic bleeds into the pelvis, and blood is very irritating. This causes widespread inflammation that can lead to pain anywhere in the back.

If you are in your second trimester of pregnancy

Your uterus is large enough to sit on the internal ducts draining urine from the kidneys. This increases pressure above the points of compression. The pain from this is typically in the flank and mid-back. It may (or may not) be accompanied by pregnancy-related vaginal discharge.

If you are in your third trimester of pregnancy

This puts you into contraction territory. Labor pains can radiate anywhere – low, mid-, and upper back – with or without the discharge of pregnancy. The blood associated with labor can be misinterpreted as a bloody vaginal discharge.

Technically, any blood is considered discharge when it comes from the vagina. This can range from microscopic leakage to brisk bleeding – the latter of which is a pregnancy emergency.

Common treatment options for back pain and vaginal discharge

When back pain and vaginal discharge are related, treating the common cause remedies both.

Infections

Antibiotics can treat bacterial infections or STIs. For yeast infections, antifungal medications are effective.

Ectopic pregnancy

Treatment is rendered medically or surgically. (Miscarriage or threatened miscarriage is always a watch-and-wait approach.)

Ligament pain

The uterosacral ligaments (which connect the cervix to the sacrum) can become inflamed by infection, which will require antibiotics. Endometriosis (in which inflammation from bloody debris remains in the pelvis can be treated with hormones or surgically. Muscle strain requires anti-inflammatories (non-pregnant only) with or without physical therapy.

When you should see your doctor about back pain and vaginal discharge

No pathological discharge (yeast, trichomonas, bacterial vaginosis, or STI) is normal, so these infections all require medical attention. When associated with back pain, this is even more important, as something more involved is going on.

You should see a doctor if:

• You have any back pain along with vaginal discharge;
• You are pregnant or may be pregnant

You should go to the emergency room if:

• You also have a fever
• The location of your back pain moves around (migrates)
• The back pain is getting worse
• You’re experiencing nausea or vomiting
• You’re bleeding from your vagina or rectum

Questions to ask your doctor about back pain and vaginal discharge

• Are the back pain and vaginal discharge coincidental or related?
• If pregnant, how could this affect my baby?
• Is the treatment the same for both?
• Is the diagnosis usually certain?

Frequently asked questions: back pain and vaginal discharge

This is a complicated issue. In order to understand the complexity, don’t hesitate to ask questions. Here are some of the most common.

What if the back pain and discharge happen suddenly or out of nowhere?

A sudden onset of back pain is always worrisome. Kidney, pregnancy, or orthopedic issues must be considered without fail.

Is back pain and discharge a sign of cancer or cervical cancer?

Pain is usually a later symptom of cancer, cervical or otherwise. Typically, there are other warning signs of cancer before there is pain and/or discharge, such as weight loss, nausea, fatigue, etc.

When back pain comes with vaginal discharge

The first priority is determining whether the discharge is physiological or pathological. Then, whether the accompanying back pain is due to a common problem or merely coincidental. Getting answers to these two questions is the first step toward proper diagnosis and effective treatment.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Lane Thaut, DO.

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