General pathology · Cell injury, adaptation and death
Hyperplasia: physiologic and pathologic !
- Process
Hyperplasia is growth of a tissue because its cells multiply. It needs cells able to divide and usually stops when the stimulus ends.
Updated 2026-11-01
What it is
Hyperplasia is an increase in the number of cells, caused by hormones or growth factors acting on cells that can divide. It may be physiologic (breast in puberty and pregnancy, the regrowing liver) or pathologic (excess hormone or growth factor). Pathologic hyperplasia remains under control and regresses when the stimulus is removed, which separates it from a neoplasm; still, some forms are fertile ground for cancer.
Step by step
- A stimulus increases: hormone, growth factor, or loss of tissue that must be replaced.
- Receptors on target cells activate signalling and push cells from G0 into the cycle.
- Mature cells divide, and stem cells add new cells.
- The tissue enlarges while keeping its normal architecture.
- When the stimulus stops, growth stops and the tissue may regress.
Classic examples
| Condition | Stimulus | Note |
|---|---|---|
| Endometrial hyperplasia | Unopposed estrogen (anovulation, obesity, estrogen therapy alone) | Abnormal bleeding; atypical form is a precursor of endometrioid carcinoma |
| Benign prostatic hyperplasia | Dihydrotestosterone acting on stromal and glandular cells | Transition zone; urinary obstruction; not premalignant |
| Graves disease | Antibodies that stimulate the TSH receptor | Diffuse hyperplasia of thyroid follicles |
| Congenital adrenal hyperplasia | High ACTH from low cortisol production | Bilateral adrenal enlargement |
| Viral warts | HPV proteins | Squamous epithelial hyperplasia |
| Liver after partial resection | Growth factors and cytokines (compensatory) | Physiologic; restores mass |
Clinical notes
- Postmenopausal bleeding needs evaluation of the endometrium to rule out hyperplasia or cancer.
- Benign prostatic hyperplasia treatments include alpha blockers (relax smooth muscle) and 5-alpha-reductase inhibitors (reduce gland size).
Test yourself
Think of the answer, then tap the question to see it.
Why can cardiac muscle not undergo hyperplasia in adults?
Adult cardiac myocytes are essentially non-dividing, so they can only enlarge (hypertrophy).
What hormone drives endometrial hyperplasia?
Estrogen without the opposing effect of progesterone.
Which prostate zone does benign prostatic hyperplasia affect, and is it premalignant?
Mainly the transition (periurethral) zone; it is not considered a precursor of prostate cancer.
Related
- Hypertrophy: physiologic and pathologic
- Metaplasia
- Liver regeneration
- Dysplasia and carcinoma in situ
- Precancerous conditions: when chronic inflammation, metaplasia or hyperplasia raise the risk
Related conditions
- Benign prostatic hyperplasia
- Endometrial hyperplasia
- Endometrial cancer
- Congenital adrenal hyperplasia due to 21-hydroxylase deficiency
- Graves disease (hyperthyroidism)
- Gynaecomastia
- Goitre
- Viral warts (verruca)
- Primary hyperparathyroidism
Elsewhere in DurgiPedia
- Cell adaptations: hypertrophy, hyperplasia, atrophy, metaplasia
- Uterus and the endometrial cycle
- Epididymis, vas deferens, seminal glands and prostate
- Cell cycle, mitosis and meiosis
- Actions of estrogen and progesterone
- Testosterone and its actions
Microorganisms
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Enlarged Prostate | BPH | Benign Prostatic Hyperplasia | MedlinePlus (MedlinePlus, US National Library of Medicine, 2024); Benign Prostatic Hyperplasia (StatPearls (NCBI Bookshelf), 2024); Endometrial Cancer (StatPearls (NCBI Bookshelf), 2024).
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Representative model, for educational purposes only.