Why Do Mattresses Sink In The Middle?

Hopping onto a brand new mattress bed can feel amazing. It’s exactly the right firmness, comfy and suited to you, and helps you sleep better at night.

Over time (or a period of 5 to 15 years), you notice your mattress begin to sag. But it isn’t just anywhere… It’s actually the center!

The edge support is great. Everywhere else feels firm. What happened to the center of the mattress?

Say Hello To Your Center of Gravity

When we walk around, we carry our weight with us. It is evenly distributed between our legs, but the center of gravity is apparent.

When you spread your legs, and one foot slips, your center of gravity is no longer balanced and makes you fall.

But when you sleep, it’s a little different. Your center of gravity, where most of your weight lies, is centered around your hips.

A brand new mattress is supportive, firm just the way you like it, and all the layers work to give you the bed sleep you need.

Compression From Our Body Weight

Over time, the layers begin to compress. The material and construction become less expansive. Memory foam and latex foam becomes compressed, coils aren’t as springy, and the base support seems to have outlived its lifespan.

All this has to do with all our body weight being concentrated at the hips.

If there is foam walls built into your mattress, it prevents the edges from caving in and allows its sleeper to use the full width of their bed. The problem in the center is that it doesn’t have the same support.

The center also lacks the least amount of support from a structural standpoint. If there was something in the middle to prevent the center from sinking, the firmness of the mattress can change drastically and make it uncomfortable to sleep on.

What Happens When The Mattress Sinks In The Middle?

This is what we look at when it comes to a mattress’s lifespan. When the center of the mattress begins to sag (the term we use to describe the deep sinking that won’t go away), the mattress has reached the end of its useful life.

There isn’t a particular number that tells you when your mattress is outlived its lifespan. Since sleep is so subjective, if your mattress becomes to cause discomfort to you, then it’s time to make the change.

You could experience the following:

  • Upper and lower back pain
  • Shoulder pain
  • Neck strain and pain
  • Hip pain
  • Constantly waking up at night from aches
  • Waking up feeling groggy
  • Bedtime is dreadful
  • You prefer sleeping on the sofa or floor
  • Increased snoring and sleep disturbance from snoring

Tips on Extending The Lifespan of Your Mattress

Sagging seems to be inevitable. However, there are a few tips to keep in mind in order to maximize the lifespan of your mattress:

  1. Avoid sitting upright on your mattress. Sagging occurs because of the compression from your body weight. When you sit, more weight is concentrated on your butt which leads to further compression of your mattress.
  2. Avoid jumping or stepping on your mattress. Like sitting, jumping or stepping on your bed will further compress the layers and material within the mattress. If you have children, keep an eye on their desire to hop on your bed!
  3. Use your bed only for sleep (and sex). Avoid spending time on your bed working, reading, or any other activities besides the two. The more time you spend on your mattress unnecessarily, the more pressure it comes under.

Does Using a Mattress Topper Help?

Adding a mattress topper is essentially adding another layer to your bed. Although it might help in the short-term, most mattress toppers aren’t enough to minimize the amount of sagging an old mattress might already have.

Mattress toppers are great if you need to adjust the firmness of your mattress, and it can help at first to extend the lifespan of your bed.

But if you are having serious problems with sleeping because the middle of your bed sinks too much, then it’s unlikely a mattress topper will help.


Mattresses sink in the middle because over time our weight, concentrated at our hips, compress the layers and construction. Although there are certain things you can do to avoid the sagging as much as possible, it is an inevitable part of the usefulness and lifespan of your bed.

Using a mattress topper might help in the short-term, but if your mattress is causing you unbearable suffering, then it might be time for a replacement.