Signs of Infection After Surgery

Статті

07.09.2026

A fresh surgical wound does not look like untouched skin: edges may be pink, mildly swollen and tender. Infection is suspected from an unfavourable trend rather than colour alone—spreading redness, increasing pain or heat, cloudy discharge, odour, fever or systemic deterioration.

I ask patients to know how the wound looked yesterday and how to contact the team. Early assessment helps identify the cause and treatment. Conversely, a drop of clear fluid, a visible thread or a small crust is not automatically infection.

Do not remove a dressing outside the plan, squeeze discharge or start leftover antibiotics. This can damage tissue, alter culture results and delay appropriate treatment.

Expected healing versus concerning change

Feature	More often expected	Contact the surgical team
Redness	Thin, limited to edges and not spreading	Expands, brightens or develops streaks
Pain	Gradually improves and remains controlled	Worsens after improvement or becomes throbbing
Swelling	Stabilises and slowly decreases	Suddenly enlarges, becomes hot and painful
Discharge	Small clear or pale-pink amount if expected	Thick yellow, green, cloudy or offensive fluid
Wound edges	Apposed without progressive defect	Separate, darken or expose deeper tissue
General state	Gradual improvement	Fever, chills, weakness or confusion

Expectations depend on suture, glue, strips, body site and postoperative day. Personal discharge instructions take priority over internet images.

A useful daily check

Element	How to assess	What to record
Colour	Similar neutral or daylight conditions	Whether redness extends beyond its prior border
Swelling	Compare sides without hard pressure	New asymmetry or tension
Pain	Consider the trend before the next pain dose	Location and new character
Discharge	Inspect dressing or drain	Colour, clarity, smell and amount
Temperature	Same thermometer and method	Time, value and medicines taken
General health	Breathing, weakness, fluids and urine	Any rapid deterioration

Do not touch the wound merely to smell or test warmth. Wash hands before an authorised dressing change and use only recommended materials.

Timing and risk factors

Many superficial infections appear from several days after surgery until the incision heals, although deeper or implant-related infection can present later.

Risk may be increased by:

poorly controlled diabetes;
nicotine and smoking;
immune suppression or corticosteroids;
undernutrition;
prolonged or complex surgery;
compromised tissue perfusion;
contamination or incorrect wound care.

A risk factor does not guarantee infection, and its absence does not exclude one.

What to do when concerned

Record the postoperative day, onset and symptom trend.
Measure temperature and assess overall condition.
Take a clear unfiltered photograph in neutral light.
Do not squeeze the wound or remove glue or sutures.
Call the surgical team that day.
Follow instructions for examination, culture, dressing or medicine.
Call emergency services for emergency signs rather than waiting for chat.

See fever after surgery and seroma after surgery for related distinctions.

How clinicians investigate and treat it

Examination establishes whether the problem is superficial or potentially deeper. Discharge may be sampled for microbiology, while ultrasound can identify a fluid collection when indicated.

Treatment can include:

local care and professional dressings;
an antibiotic selected for the clinical situation;
opening a small area to permit drainage;
draining an abscess or infected collection;
removing non-viable tissue;
intravenous treatment and admission for deeper disease.

An antibiotic alone may not cure a closed abscess; drainage can be essential.

Emergency warning signs

rapidly spreading redness with high fever or shaking chills;
confusion, fainting or profound drowsiness;
rapid or difficult breathing or chest pain;
severe weakness, fast heartbeat or cold sweat;
darkening skin, blistering or disproportionate pain;
repeated vomiting and inability to drink;
a widely opened or actively bleeding wound.

These may indicate deep infection, sepsis, impaired circulation or another complication.

What not to do

do not use alcohol, peroxide or iodine unless prescribed;
do not apply creams, powders or herbal remedies;
do not reuse an old dressing;
do not take another person’s or leftover antibiotic;
do not stop a prescribed course early;
do not heat a painful area;
do not wait for pus to “drain itself”.

Frequently asked questions

Does infection always cause fever?

No. Local infection can produce redness, pain, warmth or discharge without high fever.

Is clear fluid pus?

Not necessarily. It may be serous fluid, but increasing output or an uncertain source needs assessment.

Is a culture always required before antibiotics?

Sometimes, but not if it would dangerously delay urgent treatment. The clinician decides from severity.

Can I send a photograph and wait?

A photograph helps triage. Rapid deterioration, severe pain, fever or systemic symptoms require a call and examination.

The central point

Postoperative infection is recognised by direction of change: redness, warmth, pain, drainage and wellbeing worsen instead of improve. I ask patients to check regularly, avoid manipulating the wound and contact us early. Effective treatment may require drainage or tissue care as well as antibiotics.

Sources

Medically reviewed by Anna Brodska, plastic surgeon. Updated 7 September 2026.

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