As an Orthopaedic surgeon, one of the most common questions I hear after knee replacement, hip replacement, knee surgery, or ankle surgery is:
“Is this swelling normal?”
The answer, in most cases, is yes.
Swelling is one of the body’s normal healing responses after surgery. Although it can be uncomfortable—and sometimes alarming—it is an expected part of recovery. Knowing what is normal (and what isn’t) can help reduce anxiety and allow you to focus on rehabilitation.
Why Does Swelling Occur?
Surgery creates controlled trauma to the body’s tissues. In response, your immune system increases blood flow to the area and releases inflammatory chemicals that begin the healing process.
This results in:
- Increased blood flow
- Leakage of fluid into surrounding tissues
- Temporary inflammation
- Bruising and warmth around the surgical site
While swelling can feel frustrating, it is actually part of normal tissue repair.
One important point that surprises many patients is that the swelling you see is not always where the surgery was performed. After a hip replacement, bruising and swelling often track down into the thigh or even the knee. After knee surgery, swelling commonly settles into the calf, ankle and foot because gravity naturally pulls fluid down the leg.
When Does Swelling Peak?
Many patients expect swelling to be worst immediately after surgery.
In reality, it often continues to increase for several days.
Studies following patients after total knee replacement show swelling generally peaks between day 3 and day 8 after surgery before gradually beginning to improve. (PubMed)
This is one of the reasons patients sometimes feel they are “going backwards” during the first postoperative week, when in fact they are following a completely normal recovery pattern.
How Long Does Swelling Last?
The honest answer is longer than most people expect.
Although every patient heals differently, typical recovery looks something like this.
Hip Replacement
After a hip replacement, swelling usually begins improving after the first week.
Most patients notice a significant improvement over 6–12 weeks, although mild swelling after prolonged walking or exercise can continue for several months.
Because the hip is surrounded by large muscle groups, bruising and swelling often travel down the thigh and into the knee before gradually resolving.
Knee Replacement and Knee Surgery
Following knee replacement or other major knee surgery, swelling tends to be more obvious because there is relatively little soft tissue covering the joint.
Most patients experience:
- Maximum swelling during the first postoperative week
- Gradual improvement over the first 6–12 weeks
- Ongoing fluctuations with increased activity for several months
- Mild warmth or intermittent swelling for up to 12 months
Interestingly, newer research suggests that a small degree of increased fluid around the knee may persist much longer than patients realise, even when pain and function have improved substantially. (PubMed)
Ankle Surgery
Swelling after ankle surgery often lasts the longest.
Because the ankle sits at the lowest point of the leg, gravity continually encourages fluid to collect there whenever you are standing or sitting. While arterial blood is actively pumped into the leg with pressure from the heart, there is no active mechanism that pulls the blood back to the heart. Blood and its associated fluid has to travel back by the one-way valve system of the veins as well as the pumping action of the surrounding muscles, which are often not very active during the recovery period.
Many patients notice:
- Increased swelling towards the end of the day
- Improvement overnight after lying flat
- Recurrence after prolonged walking
Minor swelling can continue for 6–12 months, particularly after busy days.
What Patients Commonly Experience
Many patients worry because:
- their swelling seems worse during weeks 2–4 than expected
- their foot becomes swollen even though surgery was on the knee
- swelling increases after physiotherapy
- one good day is followed by a more swollen day
In reality, these fluctuations are extremely common and normal.
One of the biggest milestones in recovery is when patients begin walking more confidently. As activity increases, so does blood flow—and often, so does swelling. This temporary increase does not necessarily mean damage has occurred. Many patients also report that swelling is minimal first thing in the morning but progressively increases throughout the day, particularly after prolonged standing or walking.
What Actually Helps?
The good news is that there are several evidence-based ways to minimise swelling during recovery.
Ice (Cryotherapy)
Ice remains one of the simplest and most effective treatments.
Applying cold packs helps reduce inflammation, decreases pain and can lessen swelling, particularly during the first two postoperative weeks.
Aim for approximately 15–20 minutes at a time, several times each day, while protecting the skin with a towel or cloth. Systematic reviews continue to support cryotherapy as a useful part of early recovery after knee replacement. (PMC)
Elevation
Elevation works best when the operated leg is above the level of your heart, allowing gravity to assist fluid drainage.
Simply resting your foot on a small stool while sitting is often not enough.
For knee and ankle surgery, lying flat with your leg supported on pillows is generally much more effective.
Compression
Compression stockings or compression garments can help reduce fluid accumulation and improve comfort.
Emerging evidence suggests appropriately applied compression may reduce peak swelling during the early recovery period after knee replacement. (AccScience)
Keep Moving—But Don’t Overdo It
One misconception is that swelling means you should stop moving altogether.
In fact, gentle walking, ankle pumps and physiotherapy exercises help activate the calf muscles, which act as a natural pump to move fluid back towards the heart.
The key is balance.
If swelling increases significantly after exercise and remains elevated into the following day, it may simply be your body’s way of telling you to ease back temporarily before gradually progressing again.
When Should Swelling Be Investigated?
Although swelling is expected after surgery, there are situations where it should not simply be ignored.
Call Triple Zero (000) immediately for chest pain, sudden shortness of breath, coughing blood or collapse. Do not wait for a routine reply from the practice.
For the following other symptoms, seek urgent medical assessment:
sudden marked swelling of the entire leg
increasing calf pain
- redness spreading around the wound
- wound leakage
- fever or feeling generally unwell
worsening pain or swelling after initial improvement
These symptoms may indicate complications such as infection or a blood clot and require urgent medical assessment.
The Bottom Line
One of the most reassuring things I tell my patients is this:
Swelling is common during healing, but new or worsening swelling may need medical assessment.
Recovery after hip replacement, knee replacement, knee surgery, or ankle surgery is rarely perfectly linear. Some days your leg will look and feel better than others, particularly as you become more active.
With time, appropriate rehabilitation, sensible activity progression and patience, swelling almost always improves.
The information above is intended as general education only and should not replace advice from your own treating doctor or orthopaedic surgeon. Every recovery is unique, and if you are concerned about your progress, it is always best to seek personalised medical advice.
