10 Warning Signs and Symptoms of Pituitary Tumors You Should Know

Pituitary tumors are abnormal growths that develop in the pituitary gland, a small pea-sized organ located at the base of the brain. While most pituitary tumors are benign (non-cancerous) and called pituitary adenomas, they can still cause significant health problems by affecting hormone production or pressing on nearby structures. Understanding the symptoms of pituitary tumors is crucial for early detection and proper management.

The pituitary gland is often referred to as the “master gland” because it controls many other hormone-producing glands in the body. When a tumor develops, it can either produce excess hormones (functioning tumor) or cause hormone deficiencies by compressing the normal gland tissue (non-functioning tumor). Symptoms vary depending on the tumor’s size, location, and whether it affects hormone production.

Below are the most common warning signs and symptoms that may indicate the presence of a pituitary tumor:

1. Persistent Headaches

Headaches are one of the most common symptoms of pituitary tumors, occurring in approximately 60% of patients. These headaches typically result from the tumor putting pressure on the surrounding brain structures and the dura mater (the membrane covering the brain).

Characteristics of pituitary tumor headaches include:

• Usually felt in the forehead or behind the eyes
• Can range from mild to severe in intensity
• May be constant or intermittent
• Often worse in the morning
• May not respond well to over-the-counter pain medications

The headache pattern can vary significantly between individuals. Some people experience dull, aching pain, while others describe sharp or throbbing sensations. If you’re experiencing persistent headaches that differ from your usual headache pattern, it’s important to consult a healthcare provider.

2. Vision Problems and Visual Field Defects

Vision disturbances are a hallmark symptom of larger pituitary tumors, particularly those that extend upward and compress the optic chiasm—the point where the optic nerves from both eyes cross. This compression can lead to characteristic visual field defects.

Common vision-related symptoms include:

• Bitemporal hemianopsia: Loss of peripheral (side) vision in both eyes, often described as “tunnel vision”
• Blurred vision or decreased visual acuity
• Double vision (diplopia) if the tumor affects eye movement nerves
• Difficulty seeing objects to the side while looking straight ahead
• Sudden vision loss in severe cases

Vision problems from pituitary tumors often develop gradually, and patients may not notice them immediately. You might find yourself bumping into objects on the sides, having difficulty driving, or missing things in your peripheral vision. Any unexplained vision changes warrant immediate medical evaluation, as prolonged pressure on the optic nerves can lead to permanent vision loss.

3. Unexplained Fatigue and Weakness

Chronic fatigue and generalized weakness are frequent complaints among individuals with pituitary tumors. This symptom can result from various hormonal imbalances caused by the tumor affecting the pituitary gland’s normal function.

The fatigue associated with pituitary tumors often:

• Persists despite adequate rest and sleep
• Interferes with daily activities and work performance
• May be accompanied by muscle weakness
• Can progressively worsen over time
• May be related to low cortisol, thyroid hormone, or growth hormone levels

This type of fatigue differs from normal tiredness—it’s a profound exhaustion that doesn’t improve with rest. Patients often describe feeling drained of energy, having difficulty concentrating, and struggling to complete routine tasks. The weakness may be more pronounced in the muscles of the arms and legs, making activities like climbing stairs or carrying groceries challenging.

4. Menstrual Irregularities in Women

Women with pituitary tumors frequently experience changes in their menstrual cycles. This is particularly common with prolactin-secreting tumors (prolactinomas), which are the most prevalent type of functioning pituitary adenoma.

Menstrual symptoms may include:

• Irregular periods or oligomenorrhea (infrequent menstruation)
• Amenorrhea (complete absence of menstrual periods)
• Lighter or heavier menstrual flow than usual
• Difficulty conceiving or infertility
• Loss of libido (sexual desire)

These menstrual irregularities occur because elevated prolactin levels or deficiencies in other reproductive hormones disrupt the normal menstrual cycle. Young women may experience delayed puberty, while women of reproductive age might have difficulty getting pregnant. Postmenopausal women might not notice these symptoms, making diagnosis more challenging in this age group.

5. Abnormal Breast Milk Production (Galactorrhea)

Galactorrhea—the spontaneous production of breast milk unrelated to childbirth or nursing—is a distinctive symptom of prolactin-secreting pituitary tumors. This can occur in both women and men, though it’s more noticeable in women.

Key features of galactorrhea include:

• Milky white discharge from one or both nipples
• Can occur spontaneously or when the breast is squeezed
• May range from a few drops to significant amounts
• Often accompanied by menstrual irregularities in women
• In men, may be subtle and go unnoticed

Prolactinomas cause the pituitary gland to overproduce prolactin, the hormone responsible for milk production. In women who are not pregnant or breastfeeding, any breast discharge should be evaluated by a healthcare provider. While galactorrhea can have other causes, persistent unexplained milk production warrants investigation for a possible pituitary tumor.

6. Sexual Dysfunction and Decreased Libido

Both men and women with pituitary tumors commonly experience changes in sexual function. These symptoms result from hormonal imbalances, particularly involving prolactin, testosterone, and other reproductive hormones.

In men, symptoms may include:

• Erectile dysfunction or difficulty maintaining erections
• Decreased sexual desire
• Reduced fertility or low sperm count
• Decreased muscle mass
• Gynecomastia (enlarged breast tissue)

In women, symptoms may include:

• Reduced interest in sexual activity
• Vaginal dryness
• Painful intercourse
• Difficulty achieving orgasm
• Infertility

These sexual health issues can significantly impact quality of life and relationships. High prolactin levels suppress the production of sex hormones (testosterone in men, estrogen in women), leading to these symptoms. Many people feel embarrassed to discuss sexual problems, but these symptoms are important indicators that should be reported to a healthcare provider.

7. Changes in Facial Features and Body Composition (Acromegaly)

When a pituitary tumor produces excess growth hormone, it leads to a condition called acromegaly in adults. This results in gradual, progressive changes in physical appearance that may develop so slowly that they go unnoticed for years.

Characteristic features of acromegaly include:

• Facial changes: Enlarged nose, protruding jaw, prominent brow, thickened lips, and widened spaces between teeth
• Hand and feet enlargement: Increased shoe, ring, or glove size
• Thickened, oily skin with increased sweating
• Deepening of the voice
• Joint pain and limited mobility
• Enlarged tongue
• Sleep apnea

These changes occur because excess growth hormone causes bones and soft tissues to grow abnormally. Family members who see the person regularly may not notice the gradual changes, which is why comparing old photographs can be helpful in identifying these alterations. Acromegaly can also cause serious complications affecting the heart, joints, and metabolic health if left untreated.

8. Weight Changes and Metabolic Disturbances

Pituitary tumors can cause significant weight changes and metabolic problems due to their effects on various hormone systems. The type and direction of weight change depend on which hormones are affected.

Weight-related symptoms may include:

• Weight gain: Particularly with Cushing’s disease (excess cortisol production), characterized by central obesity, fat accumulation around the face (“moon face”), and between the shoulders (“buffalo hump”)
• Unexplained weight loss: May occur with hypopituitarism (underactive pituitary gland)
• Difficulty losing weight despite diet and exercise
• Changes in appetite
• Increased thirst and urination (with diabetes insipidus)

Metabolic disturbances can also include high blood sugar levels, elevated cholesterol, and high blood pressure. These metabolic changes aren’t just cosmetic concerns—they can increase the risk of diabetes, cardiovascular disease, and other serious health conditions. The distribution of weight gain in Cushing’s disease is particularly distinctive, with fat accumulating in the trunk while the arms and legs remain relatively thin.

9. Mood Changes and Psychological Symptoms

Hormonal imbalances caused by pituitary tumors can significantly affect mental health and emotional well-being. These psychological symptoms are often underrecognized but can be among the most distressing for patients.

Common mood and cognitive symptoms include:

• Depression and persistent sadness
• Anxiety and increased worry
• Irritability and mood swings
• Memory problems and difficulty concentrating
• Emotional instability
• Social withdrawal
• Decreased motivation

These symptoms can result from direct hormonal effects on brain chemistry or may be secondary to dealing with other physical symptoms. Low thyroid hormone, low cortisol, or altered sex hormone levels can all contribute to mood disturbances. The psychological impact of pituitary tumors is real and significant—it’s not “all in your head” but rather a direct consequence of hormonal changes affecting brain function. Mental health symptoms should be taken seriously and addressed as part of comprehensive care.

10. Nausea, Vomiting, and Hormonal Crisis Symptoms

In some cases, particularly with larger tumors or sudden tumor growth (pituitary apoplexy), patients may experience more acute and severe symptoms requiring urgent medical attention.

Warning signs of potential pituitary crisis include:

• Sudden severe headache (often described as “the worst headache of my life”)
• Nausea and vomiting
• Confusion or altered mental status
• Sudden vision loss
• Weakness and dizziness
• Low blood pressure
• Loss of consciousness in severe cases

Pituitary apoplexy occurs when a tumor suddenly bleeds or the tumor tissue dies due to lack of blood supply. This is a medical emergency requiring immediate treatment. Additionally, chronic nausea can occur with various pituitary hormone imbalances, particularly with low cortisol levels (adrenal insufficiency) or high calcium levels (which can occur with some hormonal imbalances). Any sudden worsening of symptoms or acute severe symptoms should prompt immediate emergency medical evaluation.

Main Causes of Pituitary Tumors

The exact cause of most pituitary tumors remains unknown, but researchers have identified several factors that may contribute to their development:

Genetic Factors: Most pituitary tumors occur sporadically without a clear hereditary pattern. However, certain genetic conditions increase the risk:

• Multiple Endocrine Neoplasia type 1 (MEN1): An inherited condition causing tumors in multiple endocrine glands, including the pituitary
• Familial isolated pituitary adenoma (FIPA): A rare hereditary condition where pituitary tumors run in families
• Carney complex: A genetic disorder associated with various tumors, including pituitary adenomas
• McCune-Albright syndrome: A genetic condition that can include pituitary tumors along with bone and skin abnormalities

Cellular Mutations: Pituitary tumors develop when cells in the pituitary gland undergo genetic mutations that cause them to grow and divide uncontrollably. These mutations typically occur in genes that regulate cell growth and division, though they are acquired during a person’s lifetime rather than inherited.

Hormonal Factors: Some evidence suggests that hormonal stimulation may play a role in certain pituitary tumor types. For example, prolonged high levels of hormones that stimulate the pituitary gland might contribute to tumor development in some cases.

Age and Gender: While not causes per se, certain factors affect risk:

• Pituitary tumors can occur at any age but are most commonly diagnosed in older adults
• Some types, like prolactinomas, are more common in women
• Growth hormone-secreting tumors are equally common in men and women

It’s important to note that in the vast majority of cases, pituitary tumors develop spontaneously without any identifiable cause or risk factor. They are not caused by lifestyle factors, diet, stress, or environmental exposures. Most people who develop pituitary tumors have no family history or genetic predisposition.

Frequently Asked Questions

How common are pituitary tumors?

Pituitary tumors are relatively common, accounting for about 10-15% of all brain tumors. Studies suggest that small, clinically insignificant pituitary tumors may be present in up to 20% of the general population, though most never cause symptoms and are discovered incidentally. Clinically significant pituitary tumors that require treatment are less common, affecting approximately 1 in 1,000 people.

Are pituitary tumors cancerous?

The vast majority of pituitary tumors (over 99%) are benign adenomas, meaning they are not cancerous and do not spread to other parts of the body. Pituitary carcinomas (cancerous tumors) are extremely rare. However, even benign pituitary tumors can cause serious health problems due to hormone overproduction or compression of nearby structures.

Can pituitary tumors go away on their own?

Most pituitary tumors do not disappear spontaneously. Small, non-functioning tumors may remain stable for years without growing or causing symptoms, but they rarely shrink on their own. Some very small tumors detected incidentally may never require treatment and can simply be monitored with regular imaging. Treatment decisions depend on tumor size, symptoms, and hormone levels.

What is the difference between a functioning and non-functioning pituitary tumor?

Functioning pituitary tumors actively produce and secrete excess hormones, causing symptoms related to hormonal imbalances (such as Cushing’s disease, acromegaly, or hyperprolactinemia). Non-functioning tumors do not produce excess hormones but can still cause symptoms by compressing the normal pituitary gland or nearby structures, leading to hormone deficiencies, headaches, or vision problems.

How are pituitary tumors diagnosed?

Diagnosis typically involves multiple steps: blood tests to measure hormone levels, vision testing to check for visual field defects, and imaging studies—primarily MRI scans—to visualize the pituitary gland and detect tumors. Sometimes additional specialized hormone stimulation or suppression tests are needed to fully characterize the tumor type and its hormonal effects.

What size pituitary tumor is considered large?

Pituitary tumors are classified by size as either microadenomas (less than 10 mm or 1 cm in diameter) or macroadenomas (10 mm or larger). Macroadenomas are more likely to cause symptoms from compression of surrounding structures, while microadenomas more commonly cause symptoms related to hormone overproduction.

Can stress cause pituitary tumors?

No, there is no scientific evidence that stress causes pituitary tumors. These tumors develop due to genetic mutations in pituitary cells, and the causes of these mutations are not related to psychological stress or lifestyle factors. While stress can affect hormone levels and overall health, it does not cause tumors to form.

Who should I see if I suspect a pituitary tumor?

Start with your primary care physician, who can perform initial evaluations and blood tests. If a pituitary tumor is suspected, you’ll likely be referred to an endocrinologist (hormone specialist) for comprehensive hormonal evaluation. If imaging confirms a tumor, you may also see a neurosurgeon specialized in pituitary surgery and/or an ophthalmologist for vision assessment. A multidisciplinary team approach is often best for managing pituitary tumors.

References:

• Mayo Clinic – Pituitary Tumors
• Johns Hopkins Medicine – Pituitary Tumors
• American Cancer Society – Signs and Symptoms of Pituitary Tumors
• National Institute of Diabetes and Digestive and Kidney Diseases – Pituitary Tumors
• National Center for Biotechnology Information – Pituitary Adenoma
• Pituitary Society – Pituitary Tumors