Your rectus abdominis is the major muscle in your abdomen. This long and flat band of fibers, which extends from your pubic bone to just under your ribs, sits over your organs and helps to keep them in place.

The muscle is divided in half, and each half is divided into three segments of connective tissue, also known as the six-pack.

If you’ve worked hard to get a six-pack, it can be a little disheartening to notice that your abs look crooked. The thing is, asymmetrical abs are pretty normal, and people with perfectly symmetrical features of any kind are few and far between.

Though there are other possible causes, most of the time uneven abs are nothing to worry about and just a matter of genetics.

There are a few different explanations as to why your abs may be uneven.

Genetics

Genetics are the most likely cause of uneven abs, which are also referred to as staggered abs.

With staggered abs, both sides of the rectus abdominis muscle are the same size, but the three segments on each side that make up the six-pack don’t line up, creating an uneven effect.

Research shows that genetics also play a role in body fat distribution. Uneven fat deposits in the abdomen might contribute to an asymmetrical appearance, though you may be able to remedy that with training.

Dysfunctional musculature

The appearance of crooked abs may have less to do with your ab muscles and more to do with other muscles in your body. The back muscles, for instance, provide stability for your spine.

Muscle damage or weakness in the back can lead to improper alignment of the spine. This can result in one side of the spine being higher, which can cause the muscles and associated connective tissues on that side to become overstretched.

The result is an offset or lopsided appearance in your six-pack.

If dysfunctional musculature is the cause, you may notice that one shoulder is higher than the other. You may also have back pain.

Imbalance from athletic training

Imbalanced training can lead to one side of your core being worked more than the other.

There’s research to support uneven muscle development in people who play sports that are predominantly one-sided, like tennis or golf. The muscles in the overworked side of the body become thicker.

The same can happen in weight training and strengthening if you favor one side more than the other when doing abdominal work. It’s possible to do this without even realizing it. Paying extra attention to posture and technique can help.

Uneven abs from scoliosis

Scoliosis is an abnormal curvature of the spine. In scoliosis, the spine can take on an S-shaped or C-shaped curve. The curvature usually develops just before puberty and is often mild, but it can become more severe over time.

Scoliosis causes one shoulder and hip to appear higher the other, which can make the abs appear uneven. There’s evidence that scoliosis causes asymmetry in some abdominal muscles, such as the transversus abdomninalis, though not the specifically the rectus abdominis.

If you have scoliosis, you may also notice that one shoulder blade is more prominent than the other. Back pain and breathing problems are also possible depending on the severity of the curve.

Having uneven abs is usually more of a cosmetic concern than a medical one. It doesn’t require treatment unless it’s caused by an underlying medical condition.

Certain exercises may help even out your abs if unbalanced training or excess fat is the cause. Plastic surgery may also be an option.

Exercises

You may be able to correct some asymmetry by exercising both sides of your core individually.

The key is to use exercises that lengthen the abdominals and those that require your spine to resist rotation. Posture and technique are key, so keep your shoulders back and down while doing the exercises.

Here are three exercises for uneven abs:

  • Side plank. Lie on your side with your forearm on the floor directly under your shoulder. Push your hip up and off the floor and hold as long as you can while keeping your body straight. Repeat.
  • Dumbbell suitcase carry. Choose a weight that’s heavy enough to provide a challenge and place it on the floor next to your foot. Flex at the hips and knees and keep your chest up to pick up the weight with one hand. Maintain a straight posture and carry the weight as far as you can before placing it on the floor and repeating with the other hand.
  • Woodchops. You can use a cable, kettlebell, or medicine ball to do this exercise. Stand with your legs shoulder-width apart and use both hands to hold the cable, kettlebell, or medicine ball above one shoulder. With your arms extended straight, pull down diagonally across your torso to the opposite knee without twisting your torso.

Uneven abs surgery

There are cosmetic surgery procedures that can be used to make your abs look more symmetrical. Liposuction can be used to remove excess fat from areas that may be making your abs look uneven and to create a more contoured appearance.

4D VASER high definition liposuction is a procedure that’s done by extracting fat and reinserting it back into the abdominal area to sculpt. The fat is used like clay to create a defined and sculpted look that can enhance and even the look of your six-pack.

Even bodybuilders who’ve dedicated years to sculpting their bodies often have staggered or uneven abs.

Just like your eye color and the shape of your toes, your abs are determined by genetics, and there’s little you can do about it outside of having cosmetic surgery.

If your appearance is causing you distress, speak to a doctor. Otherwise, having a six-pack — no matter how uneven — is something to be proud of.