Why Does My Period Leak to the Back? Why It Can Happen and What You Can Do About It

Jessica Lubahn 9 min read

Why Does My Period Leak to the Back? Why It Can Happen and What You Can Do About It

Period leakage –– it gets to the best of us.

It’s like a rite of passage that happens over and over again, at any age.

The worst kind of period leakage is when it leaks to the back of your underwear.

If you’re out and about, it’s the most visible.

If you’re fast asleep, it’s stained your sheets.

It may seem like bad luck with no rhyme or reason.

But there is a reason your period is leaking to the back.

The good news –– you can do something about it.

So keep reading to find the cause of your period leakage and what you can do to prevent it.

Table of Contents


why period leak in back

Why Does My Period Blood Leak to the Back? 4 Possible Reasons

There might be more than one culprit to blame for your period leakage to the back:

  1. Your anatomy –– Do you know exactly where your uterus is placed?
  2. Your flow –– Do you know how much blood you will lose on a certain day or time of day?
  3. Your position –– Is your sleeping position working against you?
  4. Poorly-fitted period products –– Is the fit your friend or foe?

Solve those issues and you’re on your way to moving confidently with less leakage.

#1: Your Anatomy

Every woman and every uterus is different.

Some women have a uterus that sits more forward, while others naturally tilt more toward the back.

It may be difficult to tell without the help of your physician.

But if you have chronic leakage to the back no matter what you do –– you may just be one of the unlucky few.

Still, it’s better to know your body so you can use additional reinforcements to lessen the likelihood of an accident.

#2: Your Flow

Tracking your period is the key to predicting your flow and preparing accordingly to avoid leakage.

It’s completely normal to have a heavier flow for the first couple of days of your period.

Planning ahead with precautions like …

  • What clothes to wear
  • What products to use; and
  • How often to change or check your product

… can save you from a messy and embarrassing incident.

But if your flow is so heavy that you …

  • Soak through one or more pads or tampons every hour for several hours in a row
  • Need to double up on pads
  • Need to change your pad or tampon in the middle of the night
  • Have menstrual periods lasting more than a week
  • Get blood clots the size of a quarter or bigger
  • Can’t do the things you normally would
  • Have constant pain in the lower part of the stomach; or
  • Feel tired, lack energy, or are short of breath

… you should see your doctor to identify the cause

Menorrhagia is the medical term for heavy bleeding of more than 80 milliliters or 16 soaked sanitary products that lasts longer than seven days.

Menorrhagia is most common in teenage and perimenopausal women because they tend to experience high estrogen levels and low levels of progesterone.

Still, it doesn’t matter how many periods you’ve had in your life, leakage happens to us all and is completely normal

Besides an underlying condition, no one really knows what makes some women’s flows heavier than others.

And sometimes you may still experience leakage regardless of the strength of your menstrual flow.

#3: Your Position

Are you standing up?

Sitting down? 

Lying down?

Anatomically, things can shift depending on your position. 

Not to mention –– gravity.

Unfortunately, there’s no position that is guaranteed to be leak-proof. 

Sleeping is the most common time to experience leakage, especially if you’re wearing a pad.

However, adjusting your sleeping position to lying on your back or side can make you less likely to leak.

Sleeping on your front can cause blood to move around versus sleeping on your side which helps take pressure off your abdominal muscles. 

Sleeping on your side is also great to help relieve cramps. 


period leak in back

#4: Poorly-Fitted Period Products

You put the wings on your pad too far forward. 

Your menstrual cup is too small.

You didn’t choose the right size tampon.

And now you’re leaking out the back or the sides.

There are plenty of period products to choose from, but if they are poorly fitted you’re setting yourself up for leakage.

Every woman is unique and needs the fit that’s perfect for them.

You may need to: 

  • Cover the entire crotch length of your pants with two pads
  • Choose a tampon absorbency that matches your current flow
  • Follow the suggestions to be sure you’ve got the right size cup 

Choosing the appropriate size, fit, and absorbency is key.

That's why it helps to have a period product that doesn’t just fit right but covers the whole area.

ONDRwear’s size-inclusive period panties have a unique absorbent gusset designed to catch all the extra fluid and keep menstrual blood from leaking through to your clothes (without the look and feel of a diaper). 


why does my period blood leak to the back

Leaking to the Back With a Pad

Improper positioning of your pad is the number one cause of your period leaking to the back.

Placing your pad with the wings too far back or too far forward is a sure-fire way to ruin your favorite pair of underwear. 

A crookedly installed pad will also deliver on the promise of leakage.

These days there are so many choices of pad type depending on your:

  • Flow
  • Position
  • Activity
  • Underwear

Even choosing the wrong …

  • Size
  • Length; or
  • Absorbency

… combination can cause a major mishap.

To wing or not to wing is another major question when choosing the right pad and panty collaboration.

For nighttime be sure you choose a long, winged overnight maxi pad over the ordinary pad.

The extra length means no leaks.

Overnight pads are purposely longer in the back to collect the blood that tends to pool under your bottom if you sleep on your back.

A regular pad can also end up contorted causing blood to leak out, especially if you’re a wild sleeper. 

Leaking to the Back With a Tampon

The three reasons you may be experiencing leaking to the back with a tampon are:

  1. Incorrect insertion
  2. Wrong size; and
  3. Not changing frequently enough

Inserting a tampon shouldn’t hurt and it should stay in place. 

Properly positioning your tampon can greatly diminish your chances of leaking.

Choosing the right size tampon is all about absorbency.

A regular tampon typically holds around 5 milliliters and a super-absorbency tampon holds about 12 milliliters of blood.

To put it simply –– If you chose the wrong absorbency or are waiting too long to change your tampon, you can expect an unhappy surprise.

Leaking to the Back With a Disposable Cup

Disposable menstrual cups are less likely to leak and can be safely worn inside your body for up to 12 hours at a time.

Many women choose to use a cup because they have a higher capacity than your average pad or tampon. 

Most menstrual cups can hold up to 30 milliliters, that’s equivalent to about three super-absorbency tampons. 

Leaks are generally rare if you’ve got your insertion and positioning perfected. 

Leaking to the Back With a Reusable Cup

Reusable cups pose the same likelihood of leaking as disposable cups due to:

  • Not changing frequently enough
  • Incorrect insertion; or 
  • Wrong size

If you’re experiencing leakage, it’s probably because the cup isn’t the right size for your body or it hasn’t fully opened up after insertion to create a seal. 

Leaking to the Back With Reusable Period Underwear

If you’ve been online searching for “how to not bleed through your pants” or “how to make sure your period doesn’t leak” you’ve probably heard about period underwear.

Period underwear is designed to take the place of pads, a menstrual cup, or tampons.

It wears just like regular underwear but contains special absorbent layers and a waterproof layer that keeps blood from passing through.

If you’re leaking to the back with reusable period underwear, the problem is likely because you aren’t washing your period underwear correctly.

The four easy steps to washing:

  1. Rinse any tissue or residue off in cold water 
  2. Treat stain beforehand
  3. Toss them in the washing machine (sans bleach and fabric softener)
  4. Let them air dry

ONDRwear machine-washable, period-proof underwear can hold almost 60 milliliters (or 9 teaspoons) of liquid, keeping you dry leak-free even on your heaviest day or night.


why does my period blood leak to the back

How Can I Stop My Period From Leaking Back?

Now that you have possibly identified the cause of your period leaking to the back, here are a few tips to put a stop to the leakage:

  • Be sure that you’re positioning the appropriate pad properly.
  • Double-check your tampon insertion skills.
  • Make sure you’ve got the right size cup situated perfectly.
  • Follow the directions when washing your reusable period underwear.
  • Whatever sanitary product you use, change it often.
  • For extra protection, double up on products. 


period leak

3 Reasons Why ONDRwear Is the Perfect Solution to Period Leaks

ONDRwear period underwear was created by a female urologist who wanted to end the frustration and embarrassment of leaky, bulky, and uncomfortable period products.

Utilizing super-soft, breathable, sustainable fabrics and anti-microbial modal algae lining, ONDRwear is the perfect solution to period leaks for three key reasons:

1. Super Absorbent – Designed to hold 25% more than other leading brands, our longer gusset is: 

  • Moisture-wicking
  • Odor-free; and
  • Leak-proof

2. Conforms to your body – ONDRwear comes with a reinforced waistband in a variety of styles to move and stretch no matter your size or shape.

3. Machine washable – Tossing your environmentally-friendly ONDRwear in the machine means you can ditch all the plastic and chemicals found in menstrual pads.

Don’t wait until you ruin your favorite pair of white pants.

Try ONDRwear today and never worry about leakage again.


why does my period blood leak to the back


The content in this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.