Hourglass syndrome (HS) is not an official diagnosis but a term to describe the action of habitually holding in, or “sucking in,” the stomach region. This action pulls in the lower ribs and gives the waist a smaller, hourglass shape.

HS can occur due to an underlying pain condition or as a result of poor posture. Alternatively, some people may develop HS as a result of trying to make their waist appear smaller.

Pulling in the abdominal muscles, or “stomach gripping,” can lead to uncomfortable symptoms, such as acid reflux, low back pain, and headaches.

This article discusses what HS is, as well as its causes, treatment, and prevention. Finally, we answer some common questions about HS.

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HS is the medical term for stomach gripping or routinely sucking in the abdominal muscles. This prevents the diaphragm from expanding fully and may result in shallow breathing.

Other possible symptoms of diaphragm dysfunction include:

  • Lower back pain: The diaphragm helps stabilize the lower back. In HS, the lower back muscles must work harder to compensate for diaphragm dysfunction. This can lead to persistent muscle tightness and pain in the lower back.
  • Neck pain and headaches: During breathing, the diaphragm moves downwards to expand the abdomen and inflate the lungs. In HS, the normal downward action of the diaphragm does not occur, and the neck and shoulders may move upward to compensate. This puts stress on the neck muscles, causing neck pain and headaches.
  • Acid reflux: The diaphragm helps to stop the contents of the stomach from traveling back up the esophagus. Decreased diaphragm action may increase the risk of gastroesophageal reflux disease (GERD).

Below are some potential causes of HS.

Abdominal pain

Persistent abdominal pain can cause a person to tighten their abdominal muscles, potentially resulting in HS.

Conditions that can cause abdominal pain and HS include:

Poor posture

HS involves an overtightening of the upper abdominal muscles, which gradually reduces muscle tension and strength in the lower abdominal muscles. This imbalance in abdominal muscle strength can cause postural issues.

In time, the postural issues relating to HS can result in injury to the lower back or pelvis.

Poor posture can cause other types of long-term damage, including:

Pressure to be thin

Some people may develop HS in an effort to appear slimmer. This can occur as a result of a negative body image or societal pressure to be thin.

Body image concerns appear particularly prevalent among adolescents and young adults. A 2020 study found that the prevalence of weight-control behaviors in British adolescents had steadily increased over the past 30 years.

The study examined data from three cohorts of adolescents born in the United Kingdom. Among the 2005 cohort, 28.6% of adolescents were trying to lose weight, compared with 42.2% of the 2015 cohort. Weight loss behaviors also had an association with a higher level of depressive symptoms.

In severe cases, weight-control behaviors can lead to eating disorders.

Hourglass syndrome has various causes, some of which are preventable, treatable, or both.

Below are some tips that can help with HS prevention and treatment.

Muscle relaxation

Muscle relaxation can help to address overtightening of the upper abdominal muscles.

One option for muscle relaxation is yoga. Research has shown that yoga and meditation help to lower stress levels. This, in turn, can promote muscle relaxation, including of the upper abdominal muscles.

Muscle strengthening

Exercises that help to strengthen the lower abdominal muscles can help to address an imbalance in the strength of the upper and lower abdominal muscles.

Some exercises that may help to strengthen the lower abdominal muscles include:

Leg drops:

  • Lie on the back with arms by the sides and legs straight up in the air.
  • Gradually lower both legs towards the floor, raising them again before they reach the floor.
  • Repeat.

Scissor kicks:

  • Lie on the back with arms by the sides and legs straight up in the air.
  • Slowly lower the right leg.
  • Raise the right leg before it touches the floor, and begin slowly lowering the left leg.
  • Alternate between lowering and raising each leg.

Rocking plank:

  • Assume the plank position, with the forearms flat on the floor and the elbows underneath the shoulders.
  • Using the forearms and toes for support, rock the body forward and backward while keeping the back straight.

Physical therapy

Physical therapy can help to treat HS in some cases. A physical therapist will examine a person’s posture and prescribe exercises that help to improve posture, muscle tone, and body alignment.

Psychological therapies

Psychological therapies may be beneficial for people who develop HS as a result of concerns about body image. People who experience such concerns should talk with their doctor, who may make a referral for talking therapy or cognitive behavioral therapy (CBT).

Below are some answers to common questions about HS.

What causes hourglass syndrome?

HS can have many different causes. Examples include:

  • chronic abdominal pain
  • poor posture
  • body-image concerns, or pressure to conform to social expectations about body shape

Can a person fix stomach gripping?

Stomach gripping is treatable. The type of treatment a person receives will depend on the underlying cause.

Possible treatment options for stomach gripping include:

  • medications to treat underlying conditions that may be causing abdominal pain and associated HS
  • muscle relaxation to address overtightening of the muscles due to stress
  • exercises to treat imbalances in abdominal muscle strength
  • physical therapy to correct postural and muscle-tone issues
  • psychological therapy to help treat body-image concerns

Does holding the stomach in help flatten it?

On its own, holding the stomach in is not enough to flatten it. The appearance of a person’s stomach has more to do with diet, exercise, and genetics.

Hourglass syndrome (HS) is a term that refers to habitual stomach gripping or sucking in of the abdominal muscles.

There are various potential causes of HS. Examples include abdominal pain, poor posture, and body-image concerns that may cause pressure to achieve the appearance of a smaller waist.

HS can lead to imbalances in muscle strength, postural issues, and problems with the diaphragm. The treatment for HS depends on the cause but may include muscle relaxation, exercise, physical therapy, or psychological therapy.