N

ight sweats are a common outpatient complaint, but there is no data regarding its actual frequency.

For many, night sweats can be highly disruptive of sleep, especially for those waking up in the middle of the night with their hair soaked, sheets drenched and sweat pouring off.

While this may be a side effect of hormonal changes associated with menopause, in some instances, it may be due to a more sinister cause.

When do night sweats signal a real threat to your health? One should schedule a visit to your doctor if night sweats occur persistently on a regular basis, if it interrupts sleep, and especially if it is accompanied by fever or other symptoms, such as unexplained weight loss.

There are a number of causes of night sweats, although lymphoma and tuberculosis are the two main diseases in which night sweats are a dominant symptom.

However, it may also be triggered by other causes, such as cancers such as leukemia; infections such as HIV or mononucleosis; fungal infections such as histoplasmosis or coccidioidomycosis; or brucellosis. Side effects from drugs such as antipyretics, antihypertensives, aspirin, anti-depressants or hypoglycemia agents can also play a role.

Finally, there are other causes, such as gastroesophageal reflux disease, obstructive sleep apnea or chronic alcohol abuse, among other things.

Given the long list of causes for night sweats, it is important for physicians to listen to what our patients tell us and narrow down the possibilities. What doctors do is as much an art as it is a science.

'€œI can'€™t believe I have lymphoma. All this time, I thought my night sweats were just due to the warm summer nights from the effect of global warming,'€ one of my patients once told me.

It was a Tuesday morning when Junita walked into my consultation room, nervous and tense after a long wait. Noticing her nervousness, I waited for her to relax and listened to her entire story.

Juanita said her travails began six months before she went to go see several general practitioners for her complaints of generalized itching, and night sweats.

The 23-year-old initially did not think much of her symptoms, but decided to see her family doctor when they persisted. She was initially told that her symptoms might be due to eczema or dry skin, and was given topical lotions to apply.

When the problems persisted, Juanita soughtout another doctor, who told her she might have '€œfood allergies'€ and prescribed her anti-histamines medications.

The medications did provide temporary relief, but after a few weeks, Juanita'€™s symptoms returned. Over the course of the next few months, she saw four other doctors who prescribed her more anti-histamines and topical creams '€” all to no avail.

Junita was eventually referred to an infectious disease specialist, who conducted an extensive investigation to exclude an infectious etiology.

By then, Junita had lost 5 kilograms '€” about ten percent of her normal body weight '€” and she also experienced intermittent episodes of body chills and fevers.

At that time, the blood tests for an infectious etiology were negative. Finally, a computed tomography (CT) scan of her chest and abdomen was carried out. The radiologist found a large anterior mediastinal mass and some enlarged nodes around the intestines.

These findings were suggestive of lymphoma, and Juanita was subsequently referred to me. A needle biopsy of the mass confirmed the diagnosis of Hodgkins lymphoma.

Lymphoma is a cancer that develops from lymphocytes, a type of white blood cell found in lymphoid organs such as the lymph nodes, bone marrow, tonsils and spleen. It is, simply put, a cancer of the
immune system.

These lymphomas may arise from either B lymphocytes or T lymphocytes. There are over 60 different types of lymphoma, and what my patient Junita had was just one subtype.

However, all lymphomas share some similar features. The backbone of treatment is chemotherapy.

We do not not know the cause of lymphoma for the majority of patients. But there are some known associations such as radiation exposure, occupation hazards from heavy chemical exposure, chronic infections like Epstein-Barr virus (EBV) or HIV, and environmental factors such as pollution and pesticide exposure may play a role in the development of lymphomas.

A standard work-up will include blood tests such as the tumor marker lactate dehydrogenase enzyme (LDH) test, a bone marrow biopsy and a lymph node biopsy or biopsy of any affected sites.

A full body scan, such a PET or CT scan, is often done prior to treatment and is useful in determining the extent of disease. Lymphoma is still considered one of the cancers that are highly treatable and a good proportion of patients can even be cured from their cancers.

Just take the case of Junita, for example: She has been in complete remission for five years and is now a proud mother of two beautiful daughters.

After all these years, I still remember her words '€œDr. Tay, I can'€™t believe I have lymphoma. All this time, I thought my night sweats were just due to the warm summer nights from the effect of global warming.'€

In Junita'€™s case, thankfully her trust in doctors was earned. I believe that physicians must always practice good clinical medicine, always asking the '€œwhys'€ rather than just treating the symptoms.

My advice to my patients is to pay special attention to persistent symptoms and do not ignore it. Sometimes, even a problem as benign as night sweat can turn out to be something more ominous.

The writer is a consulting medical oncologist with the Oncocare Cancer Center and a visiting consultant at the National Cancer Center in
Singapore. For more information, visit oncocare.sg.