Night sweats and unintentional weight loss are common symptoms with many possible causes — most of them benign. Anxiety, hormonal changes, and viral infections are far more common explanations than cancer. But when these symptoms persist for more than two to three weeks without a clear cause, a CT chest assessment is worth having to exclude the less common but important thoracic causes. Dr Lawrence Okiror, Consultant Thoracic and Robotic Surgeon (GMC 6150382), investigates thoracic causes at London Bridge Hospital. Where cancer is found, every case is discussed with a specialist team before any decision is made. Private appointments within 2–3 days. No GP referral required.
Last reviewed: April 2026 · Dr Lawrence Okiror FRCS(CTh) FRCSEd(CTh) · GMC 6150382
The most common causes of night sweats are anxiety, hormonal changes, and viral infections — all manageable and far more frequent than cancer. Unintentional weight loss is most often caused by poor appetite from another illness, infection, or inflammatory disease.
When night sweats are drenching, have persisted for two to three weeks, and are accompanied by unintentional weight loss without a clear cause, a CT chest scan is the right investigation. It either gives reassurance or finds something treatable at an earlier stage.
Where a thoracic cancer is found when constitutional symptoms are the main complaint, the disease is often at an earlier stage than when breathlessness or pain develop. Earlier means more treatment options and a better chance of complete treatment.
These are the thoracic causes that can present with night sweats and weight loss as prominent early symptoms. All are identifiable on CT scan. All have treatment available.
Lung cancer can cause night sweats and weight loss as early symptoms, sometimes before breathlessness or cough become prominent. Finding it at a stage where constitutional symptoms are still the main complaint means surgery and targeted therapies are more likely to be possible. Lung nodule & cancer →
Lymphoma affecting the chest or mediastinum is one of the classic causes of drenching night sweats, weight loss, and fatigue — known as B symptoms. CT identifies enlarged lymph nodes. Biopsy confirms the diagnosis. Lymphoma is highly treatable, particularly at earlier stages.
An infected fluid collection in the pleural space — an empyema — causes significant night sweats, fever, and weight loss alongside chest pain. Often follows a chest infection that has not fully resolved. Drainage and antibiotics treat most cases. Pleural disease →
TB classically causes night sweats, weight loss, fatigue, and a persistent cough. It remains a relevant diagnosis in London. CT and sputum tests identify TB. A treatable infection. Where surgical management is needed alongside antibiotic treatment, Dr Okiror coordinates with the appropriate respiratory medicine or infectious disease team.
Every cancer case is discussed with a multidisciplinary team of specialist oncologists at the London Bridge Hospital chest MDT, which Dr Okiror attends fortnightly. Where a case needs urgent discussion, Dr Okiror has direct access to the same specialist colleagues outside the formal MDT — so no patient waits a fortnight for a decision that cannot wait. No treatment plan is made by a single doctor alone.
Questions most commonly asked by patients experiencing persistent night sweats and unexplained weight loss.
Book an Assessment →Or call Jo Mitchelson:
020 7952 2882
No GP referral required. Private appointments at London Bridge Hospital within 2–3 days. Dr Okiror will review all findings personally and give you a clear answer and a clear plan.
Jo Mitchelson, Private PA · 020 7952 2882 · pa@lungsurgeon.co.uk
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