The presentation of a patient with hypopituitarism can vary significantly; some individuals may be symptomatic while others are diagnosed following an acute collapse. The nature of the condition and the speed of progression depends greatly on the cause of the condition, which must be considered during the diagnostic process.
It is essential that the condition is diagnosed and treated as soon as possible, because untreated hypopituitarism has the potential to lead to permanent disability or death.
The family and medical history of patients are important in the diagnosis of hypopituitarism, as certain health conditions can predispose an individual to abnormal pituitary function.
Hypopituitarism may show up as any of the following:
- ACTH deficiency results in adrenocortical insufficiency
- TSH deficiency in hypothyroidism
- FSH/LH deficiency in hypogonadism
- GH deficiency as growth failure in children, or weakness in adults
- ADH deficiency as polyuria and polydipsia
A history of headache and visual field defects or diplopia may indicate the need to test for a pituitary tumor.
A patient with a strong family history of hypopituitarism is more likely to be affected than other individuals, particularly if they also have other risk factors for the condition.
Additionally, a personal medical history of head trauma, brain surgery or tumor growth in the brain is closely linked to reduced pituitary function. In fact, when a patient is diagnosed with a tumor in the brain in or near the pituitary gland, it is wise to make further investigations to monitor the function of the pituitary gland and establish if its function has been affected by the tumor.
For women with a suspected deficiency of luteinizing hormone (LH) or follicle-stimulating hormone (FSH), it is important to ask about menstrual history. Women who are not taking an oral contraceptive pill and who have a regular menstrual period are unlikely to be affected by a deficiency of these hormones. Menopausal women usually have high levels of LH and FSH, and low levels in this period are indicative of pituitary deficiency.
A high libido or sexual drive can also be indicative of LH and FSH deficiencies, particularly in men.
Symptoms of increased thirst and urination, particularly at night, can be indicative of a deficiency in antidiuretic hormone.
Many patients with hypopituitarism may have very subtle symptoms of hormone deficiencies, which may or may not be self-reported during the medical history consultation.
Other general symptoms that may be indicative of the condition include:
- Weakness and fatigue
- Decreased appetite
- Weight loss
- Sensitivity to cold
- Swollen facial features or body
During the physical examination, it may be necessary to inspect the thyroid gland, the sexual organs and the eyes, for signs of hormone insufficiency and hypopituitarism symptoms.
If features of hypopituitarism are noted in these organs, further investigations to confirm a diagnosis of hypopituitarism are required.
The level of hormones present in the blood is a useful indicator of the function of the pituitary gland and other endocrine glands which depend on it. The following hormones may be tested to investigate the various functions of the pituitary gland:
- Adrenocorticotropic hormone (ACTH)
- Thyroid stimulating hormone (TSH)
- Growth hormone (GH)
- Luteinizing hormone (LH)
- Follicle stimulating hormone (FSH)
- Estradiol or testosterone to detect hypogonadism
- Antidiuretic hormone
In some cases, a stimulation test is used to determine if there is a deficiency in certain hormones, particularly cortisol or growth hormone. This involves administration of a synthetic or bio-equivalent hormone, followed by monitoring of the level of the hormone.
In some cases, urine tests are used in the diagnostic process for hypopituitarism. A 24-hour urine collection test can help to measure the concentration of the urine, which may be a diagnostic indicator for diabetes insipidus or antidiuretic hormone deficiency.
For men with a deficiency in LH or FSH who want to father a child, a sperm analysis test may be of benefit to determine the sperm count and potency of ejaculation.
Imaging of the brain with magnetic resonance imaging may be indicated to detect the presence of a pituitary tumor or other abnormality.
Vision tests may also be useful to investigate if a tumor of the pituitary gland has affected the visual field or impaired the sight of the individual.