تعريف
The pituitary gland is in the brain. It produces several important hormones that control the production of other hormones made by glands in the body.
The pituitary gland is responsible for many body functions, including the following:
- نمو
- ضغط الدم
- Sex organ function
- Thyroid gland function
- Breast milk production and other aspects of pregnancy and birth
- Control of sugars and fats into energy or storage
- Water balance in the body
Hypopituitarism is an insufficient production of one or more hormones. It is not a common disorder. A problem in the pituitary can cause the amount of hormones from other glands to diminish as well. This can be a serious and sometimes, life-threatening problem. It will require care from your doctor.
أسباب
There are several factors which may cause this condition:
- Tumors of the pituitary gland, hypothalamus, or brain
- Poor blood supply to the pituitary gland
- صدمة الرأس
- Radiation to pituitary gland, head, or neck
- سكتة دماغية
- Infections and inflammatory diseases
- Uncommon immune system or metabolic diseases
- A rare complication after pregnancy, called Sheehan’s syndrome
- Metastatic cancer from lung, colon, prostate, or melanoma
عوامل الخطر
Factors that increase your the chance for hypopituitarism include:
- History of childhood cancer (treatment can damage the endocrine system, which controls hormones)
- الالتهابات
- علم الوراثة
- Type 1 diabetes
- فقر الدم المنجلي
- Reduced blood volume or hypovolemia
الأعراض
Symptoms often begin gradually and are not very specific since hormones control a variety of body functions. They may not be recognized for a while. Specific symptoms will depend on the type and level of hormone affected. For example:
- Growth hormone deficiency:
- Poor overall growth
- Short stature
- زيادة ضغط الدم
- Central obesity
- ضعف العضلات
- Small heart
- Thyroid-stimulating hormone deficiency:
- Sensitivity to cold
- زيادة الوزن
- إمساك
- Hair that is brittle and coarse
- Heart rate slowed
- جلد جاف
- Muscle weakness or fatigue
- Adrenocorticotropic hormone (ACTH) deficiency:
- Fatigue and weakness
- ضغط دم منخفض
- فقدان الوزن
- Increase in skin pigmentation
- انقطاع الطمث
- Follicle-stimulating hormone and luteinizing hormone deficiency:
- Infertility in men and women
- جفاف المهبل
- Loss of some gender-specific sexual characteristics (women may lose hair from their underarms, body, and pubic area)
- Reduced libido
- انقطاع الطمث
- الضعف الجنسي لدى الرجال
- ضعف العضلات
- Small testes
- Breast enlargement in men
التشخيص
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor may refer you to an endocrinologist. This is a type of doctor that focuses on hormone disorders.
Tests to determine hypopituitarism include taking a blood sample to do the following:
- Measure the levels of hormones produced by the pituitary gland
- Measure the levels of hormones produced by target endocrine glands, which are influenced by the pituitary gland
Provocative tests of pituitary function may also be done such as:
- Growth hormone-releasing hormone (GHRH) test
- Arginine stimulation test
- L-dopa
- Clonidine stimulation test
- Insulin tolerance test
- Adrenocorticotropic hormone (ACTH) stimulation test
Once the diagnosis is confirmed:
- Imaging tests (eg, an MRI)—to identify problems such as abnormal tissue and growth or shrinkage of the pituitary gland
العلاج
Talk with your doctor about the best plan for you. This condition is likely permanent, though also depends on the cause. It will likely need to be treated for life. Treatment options include:
الأدوية
If the condition is caused by a tumor, it is first treated with medications such as:
- Bromocriptine
- Cabergoline
- Octreotide
جراحة
Medication may not always work. In this case, surgery may be needed. If a tumor is involved it will be removed. Part or all of the gland may be removed as well.
Hormone replacement therapy is needed after surgery or if other hormone deficiencies are found.
العلاج بالهرمونات البديلة
When the target hormone levels are inadequate, they must be replaced. In most cases, therapy does not replace the hormones that the pituitary gland produces. Instead, the hormones of the other target glands that it stimulates are replaced. Examples include:
- Glucocorticoids (adrenal hormone) (eg, prednisone, hydrocortisone, dexamethasone)
- Thyroid hormone (eg, levothyroxine)
- Testosterone (male)—can be replaced with patches, gels, or injections
- Estrogen and progesterone (female)—can be replaced with oral pill or patches
- Growth hormone—usually a daily injection
- Antidiuretic hormone (ADH)—can be given as pill, subcutaneous injection, or nasal puff
علاج إشعاعي
Treatment with radiation may be used after drug or surgical treatment or if they have failed.
الوقاية
In general, this condition is not preventable. Be aware of the risks and symptoms. This will make early diagnosis and treatment possible.