What delays healing: infection, diabetes, nutrition, glucocorticoids, poor blood flow !

Topic

Wounds heal slowly when they are infected, poorly perfused or under pressure, or when the person has diabetes, is malnourished or takes steroids.

Updated 2026-11-01

What it is

Healing needs oxygen, nutrients, a clean wound bed and well-regulated inflammation. Anything that lowers blood flow, prolongs inflammation, weakens collagen synthesis or blunts the immune response slows it down. Infection is the single most important local cause; diabetes, malnutrition and glucocorticoids are the classic systemic ones. Most chronic wounds have more than one factor at work.

Key facts

Systemic factors: diabetes, malnutrition, vitamin and trace element deficiencies, glucocorticoids, age, smoking, cancer, kidney failure.
Local factors: infection, poor blood flow, pressure, mechanical stress, foreign bodies, necrotic tissue, wound size and location.
The same anti-fibrotic effect of glucocorticoids is used on purpose: steroid injections are a treatment for keloids.

Factors that delay healing

Factor	How it delays healing
Infection	Prolongs inflammation and increases tissue damage; the most important local cause
Diabetes mellitus	Small- and large-vessel disease, neuropathy (unnoticed trauma), poor neutrophil function, glycation of collagen
Poor perfusion	Atherosclerosis (arterial ulcers) or venous hypertension (venous ulcers) limit oxygen and nutrient delivery
Pressure and movement	Pressure blocks capillary flow (pressure injury); movement and tension tear new tissue
Foreign bodies and necrotic tissue	Keep inflammation going and shelter bacteria
Protein-energy malnutrition	Less collagen and matrix synthesis; weaker immunity
Vitamin C deficiency (scurvy)	Defective hydroxylation of proline and lysine: unstable, weak collagen
Zinc and copper deficiency	Zinc: cofactor of metalloproteinases and cell proliferation; copper: lysyl oxidase cross-linking
Glucocorticoids	Suppress inflammation and TGF-β, reduce collagen synthesis: weak scars
Other	Older age, smoking (vasoconstriction, hypoxia), radiation, chemotherapy, obesity, uraemia, cancer

Clinical notes

The diabetic foot ulcer combines neuropathy, ischaemia and infection; it is a leading cause of non-traumatic amputation.
Pressure injuries form over bony prominences (sacrum, heels, hips) in people who cannot move; repositioning and nutrition are central to prevention.
Venous ulcers sit above the medial malleolus and are shallow; arterial ulcers are on the toes and pressure points, painful and punched out.

Test yourself

Think of the answer, then tap the question to see it.

Why does vitamin C deficiency impair healing?

Vitamin C is the cofactor of prolyl and lysyl hydroxylases; without it collagen chains cannot form stable triple helices, so scars are weak.

How does diabetes delay healing?

Vascular disease reduces perfusion, neuropathy allows unnoticed injury and pressure, and hyperglycaemia impairs neutrophil function and favours infection.

How do glucocorticoids affect a healing incision?

They suppress inflammation and TGF-β, reducing collagen synthesis and fibrosis, so the scar is weaker and dehiscence more likely.

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Elsewhere in DurgiPedia

In Pharmacology

Corticosteroids (glucocorticoids)

← All of general pathology

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: Scurvy: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Venous Leg Ulcer (StatPearls (NCBI Bookshelf), 2024); Pressure Sores | Bedsores | Pressure Ulcers | MedlinePlus (MedlinePlus, US National Library of Medicine, 2026); 4.6 Tissue Injury and Aging (OpenStax (Anatomy and Physiology 2e), 2022).

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