Post-Operative Complications: What to Watch For After Surgery
Most surgical recoveries go smoothly. But knowing what to watch for (and what is normal) can help you feel more in control. This guide covers the complications patients most commonly worry about, what published clinical guidelines say about them, and when it may be appropriate to contact your healthcare team.
Surgical site infection is one of the most commonly discussed postoperative complications. Published NICE guidelines (CG74) define SSI as an infection occurring within 30 days of surgery (or within a year if an implant is involved). Most surgical wounds heal without infection, but awareness of the signs can help patients seek early assessment.
- Increasing redness that spreads outward from the wound edges
- Warmth or heat around the wound site
- Discharge that is cloudy, yellow-green, or has an unpleasant smell
- Fever above 38°C (100.4°F)
- Increasing pain around the wound rather than gradual improvement
- Mild redness immediately around the wound edges in the first few days
- Clear or slightly blood-tinged fluid (serous drainage) in the early days
- Minor swelling around the incision site
- Slight warmth at the wound: part of the normal inflammatory healing process
- Redness that is spreading rather than staying stable or fading
- Fever that persists or is above 38°C
- Pus or foul-smelling discharge from the wound
- Wound edges opening up (dehiscence)
- Red streaks running away from the wound
Deep vein thrombosis (DVT) (a blood clot in a deep vein, usually in the leg) and pulmonary embolism (PE) (when a clot travels to the lungs) are serious but preventable postoperative complications. NICE guideline NG89 provides detailed recommendations for VTE prevention in surgical patients.
- DVT: Pain or tenderness in the calf, swelling in one leg (not both), redness or warmth over the affected area
- PE: Sudden shortness of breath, chest pain (especially when breathing in), coughing up blood, feeling faint or dizzy
- Reduced mobility after surgery (especially bed rest)
- Major orthopaedic, abdominal, or pelvic surgery
- Active cancer or cancer treatment
- Dehydration
- Personal or family history of blood clots
- Obesity, smoking, and use of hormonal contraception or HRT
- Early mobilisation: getting moving as soon as your team says it is safe
- Compression stockings (TED stockings) as prescribed
- Anticoagulant injections or tablets as prescribed by your team
- Staying hydrated: drinking water regularly
- Ankle pump exercises while in bed or sitting
Wound healing is a complex process that can sometimes take longer than expected. Some patients may experience delayed healing, wound dehiscence (where the wound edges separate), or excessive granulation tissue. Factors such as diabetes, smoking, poor nutrition, and certain medications can affect how wounds heal.
- Itching around the wound: often a sign of healing
- Slight puckering or unevenness of the skin edges
- Mild redness that gradually fades over days to weeks
- A small amount of clear or slightly pink drainage in the first few days
- Wound edges visibly separating (dehiscence): especially if tissue is visible underneath
- Persistent drainage beyond 2 weeks that is not improving
- Bright red, beefy-looking tissue protruding from the wound (over-granulation)
- A wound that was healing well but suddenly deteriorates
- Complete wound breakdown after abdominal surgery: seek urgent help
A seroma is a collection of clear fluid (serum) that can build up under the skin near a surgical wound. A haematoma is a collection of blood. Both are relatively common after surgery, particularly after procedures that involve significant tissue dissection such as mastectomy, hernia repair, or abdominoplasty.
- Some swelling around the wound site in the first week or two
- Bruising that changes colour from dark purple to yellow-green over 2–3 weeks
- A soft, fluctuant (squishy) area near the wound that is not painful and not growing
- A fluid-filled swelling under the skin near the wound: sometimes described as feeling like a water balloon
- Usually not very painful, but can feel uncomfortable or heavy
- Many small seromas resolve on their own over weeks
- Rapidly expanding swelling: especially in the first 24–48 hours (may suggest active bleeding)
- A firm, tense, painful lump that is growing (possible haematoma)
- Signs of infection developing over the swelling — redness, warmth, fever
- The swelling is affecting your ability to move or function
Surgery can sometimes affect nerves near the surgical site. This may result in altered sensation, numbness, or neuropathic pain. Some patients describe this as burning, tingling, shooting pain, or patches of numbness. In many cases, nerve function improves over time as the body heals, though this can take weeks to months.
- Burning, tingling, or "pins and needles" sensations near the wound
- Shooting or electric-shock-like pain
- Patches of numbness or reduced sensation around the incision
- Hypersensitivity: where light touch feels uncomfortable or painful
- Temporary numbness around the wound: very common after surgery
- Altered sensation that gradually improves over weeks or months
- Occasional tingling as nerve fibres regenerate
- A "tight" or "pulling" feeling around the scar
- Numbness that is worsening rather than improving over time
- Loss of function: for example, difficulty gripping, foot drop, or muscle weakness
- Pain that is not improving after 6 weeks, or is significantly affecting sleep or daily life
- Numbness spreading to areas distant from the surgical site
All surgery that involves an incision will leave a scar. In most cases, scars mature and fade over 12–18 months. However, some patients may develop hypertrophic scars (raised and red but staying within the original wound boundary) or keloid scars (which grow beyond the original wound edges). These are more common in certain skin types and body areas.
- A scar that is red, raised, and firm for the first 6–12 months
- Itching along the scar line: very common during maturation
- Slight thickening or firmness of the scar tissue
- Gradual fading from red/pink to a paler colour over 1–2 years
- A scar that is growing beyond the original wound borders (possible keloid)
- A scar that is painful, not just itchy
- A scar that is restricting movement (contracture), particularly across joints
- Scarring that is causing significant distress or affecting quality of life
General anaesthesia, regional blocks, and sedation can all produce aftereffects that some patients find unexpected. The Royal College of Anaesthetists provides detailed patient information about what to expect. Most aftereffects are temporary and resolve within hours to days.
- Nausea and vomiting: can affect up to 30% of patients after general anaesthesia
- Fatigue and drowsiness for 24–48 hours
- Sore throat or hoarse voice (from the breathing tube during intubation)
- Cognitive fog: feeling "not quite right" or forgetful for a day or two
- Shivering after waking up
- Muscle aches (from positioning during surgery or muscle relaxants)
- Feeling groggy or emotionally flat for 24–48 hours
- Mild confusion in elderly patients that may last a few days (postoperative cognitive dysfunction)
- Difficulty concentrating or making decisions for the first day
- Sore throat that resolves within 1–2 days
- Persistent vomiting that prevents you keeping fluids down
- Severe headache after a spinal or epidural anaesthetic (possible post-dural puncture headache): typically worse when upright
- Prolonged confusion, especially if worsening rather than improving
- Numbness or weakness in a limb that persists after a nerve block should have worn off
- Difficulty breathing or chest tightness
The emotional impact of surgery is often underestimated. Published research suggests that mood changes, anxiety, and even depression-like symptoms are common after major surgery. Factors such as pain, reduced independence, altered body image, and the stress of recovery can all contribute. Some patients experience PTSD-like symptoms, particularly after emergency or traumatic surgery.
- Mood swings, tearfulness, and emotional fragility in the first weeks
- Frustration with the pace of recovery
- Grief for lost function, changed appearance, or loss of independence
- Feeling unlike yourself: anaesthesia, pain medication, and poor sleep all affect mood
- Relief mixed with unexpected sadness: even when surgery "went well"
- Persistent low mood that continues beyond 2–3 weeks without improvement
- Thoughts of self-harm or feeling that life is not worth living: please reach out for support
- Inability to cope with daily activities due to anxiety or distress
- Flashbacks, nightmares, or severe anxiety related to the surgery
- Withdrawal from friends, family, or activities you normally enjoy
Published guidance is clear: the following situations may require immediate emergency medical attention. If in doubt, it is always safer to call.
This page is compiled from published clinical guidelines and trusted health information sources. No original clinical claims are made. Always verify with your own healthcare team.
- NICE CG74, Surgical site infections: prevention and treatment (2019, updated 2020). nice.org.uk/guidance/cg74
- NICE NG89, Venous thromboembolism in over 16s: reducing the risk of hospital-acquired deep vein thrombosis or pulmonary embolism (2018, updated 2019). nice.org.uk/guidance/ng89
- NICE CG173, Neuropathic pain in adults: pharmacological management (2013, updated 2020). nice.org.uk/guidance/cg173
- NHS, Wound infection, General anaesthesia, Scars, Peripheral neuropathy, Mental health. nhs.uk
- Royal College of Anaesthetists: Patient information leaflets. rcoa.ac.uk
- healthdirect Australia — Surgery and procedures. healthdirect.gov.au
- British Association of Dermatologists, Scars patient information. bad.org.uk
For a complete list of sources used across Postopcare.info, see our Sources page.
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