How lymphoedema affects a DEXA scan
A DEXA scan can still be performed in people with lymphoedema, however it is important to understand how the condition may influence the results and how clinicians interpret them.
Lymphoedema involves a build-up of lymphatic fluid in one or more limbs. Because a DEXA scan measures body composition by differentiating between bone mineral content, lean tissue and fat tissue, excess fluid can influence the readings
Important Key points to know:
Fluid is counted as lean mass. DEXA machines can not distinguish between muscle and fluid. In an affected limb, lymphatic fluid will be included in the lean mass measurement. This means:
- Lean mass may appear artificially high in the swollen limb
- Muscle mass in that limb may be overestimated
- Fat and bone measurements are usually reliable
- Bone density results are generally unaffected by lymphoedema
- Fat mass is less impacted than lean mass, but severe swelling can slightly distort regional fat distribution
- Whole-body results may still be useful
If lymphoedema is confined to one limb, total body composition can still provide helpful trend data, especially when the same conditions are used for repeated scans.
How clinicians manage this during interpretation
Experienced clinicians will:
- Note the presence and location of lymphoedema before the scan
- Focus on unaffected limbs for muscle comparisons
- Use side-to-side asymmetry cautiously, knowing swelling alters lean mass values
- Prioritise trend tracking over time rather than single scan values
In some cases, segmental analysis may be adjusted or certain limb data excluded from performance or muscle-gain assessments.
Can DEXA be used to monitor lymphoedema?
DEXA is not a diagnostic tool for lymphoedema, but it can be helpful in a supportive way:
- Monitoring changes in limb composition over time
- Identifying significant asymmetry between limbs
- Supporting broader clinical assessments alongside tape measures, bioimpedance, or clinical examination
Practical tips if you have lymphoedema
- Tell the clinic which limb is affected before your scan
- Try to keep conditions consistent for follow-up scans (time of day, compression use, hydration)
- Avoid using DEXA lean mass data alone to judge muscle gain or loss in the affected limb
- Combine DEXA results with input from your GP, physiotherapist, or lymphoedema therapist
A DEXA scan can still be performed safely and usefully in people with lymphoedema, but lean mass results in the affected area need careful interpretation. When analysed by trained clinicians, DEXA Scans remain a valuable tool for bone health, overall body composition, and long-term tracking.