What causes a person to have a moon face? A comprehensive guide to understanding and treating facial puffiness

September 21, 2025 •

4 min read

A puffy, rounded facial appearance, often called moon face, is a well-documented side effect of certain medications and underlying medical conditions. It is vital to understand what causes a person to have a moon face to address the issue effectively and safely with medical guidance.

Quick Summary

Long-term corticosteroid use is a primary cause of moon face, but it can also be a symptom of Cushing's syndrome, hypothyroidism, or weight gain. Excess cortisol and fluid retention cause fat redistribution and facial puffiness.

Key Points

Corticosteroid Use: Long-term use of steroids like prednisone is a primary cause, mimicking the body's stress hormone, cortisol, to cause fat redistribution and water retention.
Cushing's Syndrome: A hormonal disorder characterized by the body producing too much cortisol, leading to moon face, central obesity, and other symptoms.
Hormonal Imbalances: Conditions such as hypothyroidism can cause facial puffiness due to fluid buildup, a sign of an underactive thyroid.
Fluid and Diet: High sodium intake and inadequate hydration can lead to water retention, which exacerbates facial swelling and puffiness.
Treatment Depends on Cause: The appearance of moon face is often reversible by addressing the underlying cause, whether it's tapering off medication or treating a hormonal disorder.
Do Not Stop Medication Abruptly: Never stop taking corticosteroids or other prescribed medications without a doctor's supervision, as this can lead to serious health complications.
Seek Medical Guidance: Accurate diagnosis requires consulting a healthcare provider, who can use blood tests and imaging to identify the correct cause.

The Primary Culprits: Medications and Medical Conditions

Moon face is not a disease in itself but a symptom of an underlying condition or a side effect of certain treatments. Identifying the root cause is the first step toward effective management.

Long-Term Corticosteroid Use

One of the most common causes of a person having a moon face is the prolonged use of corticosteroid medications like prednisone. These powerful drugs are prescribed to treat a variety of inflammatory and autoimmune conditions, including:

Lupus and rheumatoid arthritis
Severe allergies and asthma
Certain cancers
Organ transplant rejection

The mechanism involves the drugs mimicking the body's natural stress hormone, cortisol. Excess cortisol leads to fat redistribution in the body, causing accumulation in the face, midsection, and the back of the neck (a “buffalo hump”). It also promotes water and sodium retention, further contributing to facial swelling and puffiness.

Cushing's Syndrome

Cushing's syndrome is a hormonal disorder that occurs when the body is exposed to high levels of cortisol for a prolonged period. The facial rounding, or moon face, is one of its most recognizable symptoms. The syndrome can be caused by:

Pituitary adenomas: Noncancerous tumors on the pituitary gland cause it to produce excessive amounts of adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal glands to overproduce cortisol.
Adrenal gland tumors: Growths on the adrenal glands (located above the kidneys) can cause a direct overproduction of cortisol.
Ectopic ACTH-producing tumors: In rare cases, tumors in other parts of the body (e.g., lungs, pancreas) produce ACTH.
Iatrogenic Cushing's syndrome: This is the most common cause, resulting from long-term, high-dose use of prescribed corticosteroid medications.

Hypothyroidism

An underactive thyroid gland, or hypothyroidism, can also lead to facial swelling. When the thyroid doesn't produce enough thyroid hormone, it slows down the body's metabolism. This can cause the buildup of sugar molecules in the skin that attract water, resulting in fluid retention known as myxedema. The puffiness often appears around the eyes and is accompanied by other symptoms like fatigue, weight gain, and muscle aches.

Other Factors Contributing to Facial Puffiness

While not typically the primary cause of true moon facies, other factors can exacerbate or mimic the condition:

General weight gain: Gaining overall body weight can result in a rounder facial appearance, though the fat distribution is different from that caused by Cushing's syndrome or steroids.
High sodium intake: Eating too much salt can cause the body to retain water, leading to temporary facial puffiness.
Dehydration: Paradoxically, dehydration can cause your body to hold onto fluid, contributing to swelling.
Poor sleep and stress: Lack of adequate sleep and high stress levels can increase cortisol production and hinder lymphatic drainage, resulting in facial puffiness.

Comparison Table: Common Causes of Moon Face


Cause	Underlying Mechanism	Primary Treatment	Likelihood of Reversal
Long-Term Steroid Use	Mimics cortisol, causes fat redistribution & water retention.	Tapering medication dose under medical supervision.	High, with gradual return to normal.
Cushing's Syndrome	Excess cortisol production, often due to a tumor.	Medication, surgery, or radiation therapy to address the underlying tumor.	High, with successful treatment of the cause.
Hypothyroidism	Insufficient thyroid hormone production, leading to fluid retention (myxedema).	Hormone replacement medication (e.g., levothyroxine).	High, as hormone levels are regulated.

Diagnosis and Treatment: A Physician-Guided Process

If you are concerned about developing a moon face, particularly if you are taking steroids or have other symptoms of a hormonal imbalance, it is essential to consult a healthcare provider. A doctor can perform several tests to determine the cause, including:

Blood tests: To measure cortisol and thyroid hormone levels.
Urine tests: To assess cortisol production over a 24-hour period.
Imaging scans: MRI or CT scans may be used to identify tumors on the adrenal or pituitary glands.

Treatment is entirely dependent on the diagnosis:

For steroid-induced moon face, a physician may gradually reduce the dosage. It is critical never to stop corticosteroids suddenly, as this can cause dangerous withdrawal symptoms.
For Cushing's syndrome, treatment focuses on correcting the high cortisol levels, which may involve surgery to remove a tumor, radiation, or specific medications.
For hypothyroidism, hormone replacement therapy with levothyroxine is the standard treatment.

Coping and Lifestyle Adjustments

While waiting for the underlying condition to be treated, certain lifestyle adjustments can help manage the symptoms and reduce facial swelling:

Reduce salt intake: Limiting processed foods and adding less salt to meals can help reduce fluid retention.
Stay hydrated: Drinking plenty of water helps your body flush out excess fluids.
Get enough sleep: Prioritize adequate, restorative sleep to help regulate hormone levels and support lymphatic drainage.
Engage in regular exercise: A healthy exercise routine can aid overall weight management and improve circulation.
Address stress: Practice relaxation techniques or mindfulness to help manage stress-induced cortisol levels.

For more detailed information on moon face and related conditions, you can consult reputable sources like the Cleveland Clinic.

The Reversibility of Moon Face

Is moon face a permanent condition? For most cases caused by treatable conditions or medication, the answer is no. When the underlying cause is effectively managed—whether by tapering steroid dosage, treating Cushing's syndrome, or addressing hypothyroidism—the moon face will typically subside over time as fat and fluid redistribution reverses. It is important to be patient, as the process can take several weeks or months. Focusing on the root cause with your doctor's help offers the best chance of restoring your natural facial appearance and improving your overall health.

Frequently Asked Questions

No, while moon face is a hallmark symptom of Cushing's syndrome, it can also be caused by long-term use of corticosteroid medications like prednisone. A doctor can determine the specific cause through proper testing.

The duration varies depending on the individual, the dosage, and the length of treatment. It can take several weeks to months for the facial swelling and fat redistribution to fully resolve after gradually tapering off steroids under a doctor's care.

Yes, lifestyle modifications can help manage the symptoms. Reducing salt intake, staying hydrated, getting adequate sleep, and managing overall weight can help minimize fluid retention and facial puffiness.

Moon face is not typically painful. It is characterized by swelling and fullness, which can cause discomfort, but it is not known to be a source of physical pain. However, the underlying condition might have associated symptoms.

Facial exercises are not an effective treatment for moon face. This is because moon face is caused by internal factors like hormonal imbalance or fluid retention, not weakened facial muscles. Addressing the root cause is the only way to resolve the condition.

Yes, poor sleep quality can increase the body's production of cortisol and disrupt lymphatic drainage. This can lead to increased fluid retention and facial puffiness over time.

Normal facial puffiness, often seen after waking up, is typically mild and resolves on its own within a short time. Moon face, however, is a more persistent and progressive rounding of the face due to fluid or fat, and it does not go away without addressing the underlying cause.