What is Hyperplasia?

Tricia Christensen
Tricia Christensen

Hyperplasia is an increase in the number of cells in an organ or tissue. Though this process is often harmless and sometimes even beneficial, it can also happen in connection with several illnesses. Generally speaking, all types of hyperplasia can be categorized as physiologic, or benign, and pathologic, or illness-related. This process can also be induced artificially. Regardless of whether its physiologic or pathologic, this process occurs in response to normal stimuli, as opposed to the processes that form tumors, which are abnormal stimuli.

The growth of extra milk glands during pregnancy is a natural and harmless form of hyperplasia.
The growth of extra milk glands during pregnancy is a natural and harmless form of hyperplasia.

Physiologic Types

Most people experience some type of harmless hyperplasia at some time during their lives. For instance, certain types of exercise can cause an increase in the number of muscle cells in a particular area, and pregnant women usually develop extra milk gland cells in their breasts in preparation for breastfeeding. It's also extremely common for older men to develop more cells in their prostate glands, which is known as benign prostatic hyperplasia. Some other physiologic types include focal nodular hyperplasia, which is a non-cancerous type of liver growth, and cutaneous lymphoid hyperplasia, a type of skin lesion. One rarer type is intravascular papillary endothelial hyperplasia, in which the cells lining blood vessels increase, usually in the skin of the head or neck.

Severe acne is one symptom of congenital adrenal hyperplasia.
Severe acne is one symptom of congenital adrenal hyperplasia.

Sometimes, the increase in cells is extremely beneficial. For example, this process is what allows the liver to regenerate itself even if it is extremely damaged. This is also the reason that liver transplants work — the cells in a section of donated liver can divide and increase to the point where the liver becomes functional again. Additionally, some people induce hyperplasia through injections of Insulin Growth Factor-1 (IGF-1) and Human Growth Hormone (HGH). Though this is not always dangerous, and it does tend to lead to lasting gains in muscle mass, overuse of IGF-1 and HGH is associated with the growth of breasts in men, carpal tunnel syndrome, premature baldness, aggression, and liver and kidney problems, among other things.

In some cases, polycystic ovary syndrome (PCOS) can trigger hyperplasia.
In some cases, polycystic ovary syndrome (PCOS) can trigger hyperplasia.

Pathologic Types

Though this process in and of itself usually isn't a dangerous condition, it is sometimes associated with illnesses and may be a precursor to some cancers. For instance, endometrial hyperplasia, which is an increase in the number of cells lining the uterus, is a risk factor for endometrial cancer, but can also happen in response to estrogen therapy or polycystic ovary syndrome (PCOS). Other types are more closely associated with cancer, such as C-cell hyperplasia, which is generally a precursor to medullary thyroid cancer (MTC), and oral verrucous hyperplasia, which is thought to be a precursor to verrucous carcinoma, a type of oral cancer.

Congenital adrenal hyperplasia may be associated with Cushing's syndrome.
Congenital adrenal hyperplasia may be associated with Cushing's syndrome.

Another pathologic type that is not associated with cancer is congenital adrenal hyperplasia (CAH), which affects the adrenal gland's ability to produce hormones such as cortisol and androgens. This is associated with Cushing's syndrome, and usually causes abnormal genitalia, extremely early puberty, infertility, menstrual irregularities, and severe acne. There are two forms of CAH, one of which starts in infancy and is generally more serious than the other, which starts in late childhood or early adolescence.

Symptoms and Diagnosing

The symptoms of this condition depend largely on the underlying cause. Since there are so many different types of this condition, there's no one overall method for diagnosing it, but doctors can generally determine whether a person has it by the associated symptoms or by taking and testing a sample of cells. A few types do have easily visible symptoms; for example, cutaneous lymphoid hyperplasia causes reddish-brownish nodules on the skin, and sebaceous hyperplasia causes shiny bumps on the face. Even in cases with visible symptoms, however, a doctor still usually needs a biopsy to confirm the diagnosis.


Like the diagnostic process, the treatment for hyperplasia depends on the type. In some cases, the treatment centers on the underlying cause, as with CAH, while in others hormonal injections can help. Any nodules and growths formed by this process are usually surgically removed.

Some people induce hyperplasia with insulin injections.
Some people induce hyperplasia with insulin injections.
Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent wiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

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Discussion Comments


i appreciate this citation so much. it is really more than impressive.


what are the organs/tissue where hyperplasia does not occur?


Pneumonia is an infection of one or both lungs which is usually caused by bacteria, viruses, or fungi. referring to the herpes around the patents mouth.


what are the medications to treat hyperplasia?


(1).Case abstract. Male, 59-year-old.

Chief complaints. Coma, aphasia and paralysis of right half body for one day( Told by family members on behalf of the patient).

Present medical history. From half a year ago, the legs were benumbed and the muscle of legs was atrophy; he suffered leg pain and claudication after walking, which was remitted after rest. After drinking one day ago, he suddenly suffered headache, giddiness, aphasia, coma, and paralysis of right half body, oral leaning to left and incontinence. Diagnosis in the local clinic: thrombus of the brain.

Past medical history. He was suffered from hypertension more than 30 years, and suffered headache, neck rigidity ( stiff-neck ), dizzy and giddiness, and the blood pressure was ranged from 24.6/13.3 kPa( 185/100 mmHg) to 26.6/14. 6 kPa(200/ll0 mmHg) in recent 5 years.

Physical examination. Bp is 25.3/14.6 kPa( 190/110 mmHg); heart rate is 90 times /min; body temperature is 37℃ ; and breathing per rain is 25 times. The development and nourishment was good, he was obesity, the perimeter of his abdomen was 122 cm, coma, the breath was slow and deep, oral leaning to the left, spastic paralysis of right half body, the Babinski reflex was positive, and the right physiological reflex was sthenic. The lower limbs were atrophy, lesion of the right leg was more apparent. The apical impulse was intensified, and the range of pulsation was extended. Fundus examination : The atherosclerosis of retina was thin like silver silk with high reflection, the phenomenon of arteriovenous crossing oppression, and the papilloedema of optic nerve. X-ray examination: The left boundary of the heart was extended, and the aortic arch was stood out, presented “boot-like” form. The computered tomography examination: There was the hemorrhage in left internal capsule.

Urinary routine: the urinary protein was positive(+).

Treatment. 0.5 μg/min of the sodium nitroprusside and 250 mL of the sorbite were administrated by intravenous drip, and the expectant treatment was performed by administrating hemostatic medicine, and so on.

Clinic diagnosis. Cerebral hemorrhage


1). What kind of pathological changes do this patient suffered? 2). What is consequence of this patient ? ( 2 ) Case abstract. 25-year-old, He suffered chill, fever, cough with brown sputum and chest pain for 1 week.

Present medical history. About one week ago, he feel malaise, then suffered chill, fever with body temperature 40℃. The symptoms alleviated slightly after treated by antibiotics. He still suffered chill and high fever on the second day. He developed chest pain, dry cough accompanying with brown reddish sputum then developed dyspnea in the afternoon.

Past medical history. Healthy.

Physical examination. Good nutrition, consciousness, high fever features, mandible lymph nodes swell, tenderness (+). There are herpes around mouth, congestion at pharynx. Tubular breath sound can be heard at right scapular region, no dry rales and wet rales; Heart rate: 100 times/min. Body temperature: 39.7℃, X-ray: there are large piece of clouding shadow at upper lobe of right lung.

Blood routine. WBC: 15×109/L; st: 0.19; sg: 0.76; L: 0.05.

Process of treatment. After treated by antibiotics and anti-symptom therapy, fever relieved rapidly; symptoms disappeared. He discharged after 3-week treatment.


1). What is the diagnosis of the case? 2). What lesions does this case show?

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