What’s the best diagnostic evaluation of night sweats?

Evidence summary

Night sweats are a common complaint in the ambulatory primary care setting: Of 2267 patients in 1 cross-sectional study, 41% reported night sweats, defined as “sweating at night even when it isn’t excessively hot in your bedroom” within the previous month.¹ Because the peak prevalence in both men and women occurred in the group ages 41 to 55 years, there was concern that menopausal hot flashes were a confounding factor, at least for women. In a subsequent study of 795 patients older than 64 years, 10% still reported being bothered by night sweats.²

The more common causes are not widely studied

Few studies look at the causes of night sweats. Although they have been associated with tuberculosis, lymphoma, and HIV infection, these are not common causes of night sweats in outpatient care.

In the only study that specifically addressed the causes of night sweats in an ambulatory population, Reynolds³ interviewed 200 consecutive patients, 70% from a primary care practice and 30% from a gastroenterology practice. Of the 81 patients who reported having an episode of night sweats at least once a week, esophageal reflux and menopause were the most frequent causes.

Several authors agree that certain medications are frequently associated with night sweats, although the exact incidence is unknown due to a lack of published epidemiologic data.^4-6 Antidepressants and antipyretics are among the more commonly cited offenders (TABLE 1).⁴

TABLE 1
Medications that may cause sweating or flushing

Finding the right diagnosis requires thorough history & exam

With such a long differential diagnosis (TABLE 2),^4-6 night sweats should initially be evaluated with a thorough history and physical examination (according to a consensus opinion of various authors). If these don’t elicit possible causes, the appropriate next step in the work-up can vary. Some authors recommend multiple laboratory and imaging studies, while others advise against any routine tests. None of these approaches is evidence-based.

One reasonable algorithm recommends an initial work-up including a complete blood count, thyroid-stimulating hormone (TSH) and erythrocyte sedimentation rate (ESR) level, a purified protein derivative (PPD) and HIV test, and a chest x-ray.⁵ If the results are unrevealing, a trial of antireflux medication is recommended. If the patient does not improve, consider a diary of nocturnal temperatures to help discern the presence or absence of febrile pulses and further evaluate for suspected endocarditis or lymphoma.

TABLE 2
Differential diagnosis for night sweats

Evidence is scant for symptom relief

Very few clinical trials have directly studied symptomatic relief of night sweats. A large Cochrane meta-analysis found that oral hormone therapy—estrogens alone or estrogens with progesterone—reduced the frequency of night sweats associated with hot flashes among menopausal women by 75% when compared with placebo alone.⁷ Neither primrose oil nor foot reflexology proved effective.⁸

A cohort study found that 80% of the patients with frequent night sweats responded to antireflux therapy.³ One author suggests using therapies aimed at relieving hyperhydrosis.⁶ These include local treatment with aluminum chloride hexahydrate (Drysol), antiperspirants, scopolamine, or phenoxybenzamine hydrochloride (Dibenzyline).

Recommendations from others

A thorough literature search through Cochrane Database Systematic Reviews, AHRQ, National Guideline Clearing-house, and Medline did not yield any guidelines or consensus statements from other organizations or specialty groups on the evaluation or treatment of night sweats.

Evidence summary

Night sweats are a common complaint in the ambulatory primary care setting: Of 2267 patients in 1 cross-sectional study, 41% reported night sweats, defined as “sweating at night even when it isn’t excessively hot in your bedroom” within the previous month.¹ Because the peak prevalence in both men and women occurred in the group ages 41 to 55 years, there was concern that menopausal hot flashes were a confounding factor, at least for women. In a subsequent study of 795 patients older than 64 years, 10% still reported being bothered by night sweats.²

The more common causes are not widely studied

Few studies look at the causes of night sweats. Although they have been associated with tuberculosis, lymphoma, and HIV infection, these are not common causes of night sweats in outpatient care.

In the only study that specifically addressed the causes of night sweats in an ambulatory population, Reynolds³ interviewed 200 consecutive patients, 70% from a primary care practice and 30% from a gastroenterology practice. Of the 81 patients who reported having an episode of night sweats at least once a week, esophageal reflux and menopause were the most frequent causes.

Several authors agree that certain medications are frequently associated with night sweats, although the exact incidence is unknown due to a lack of published epidemiologic data.^4-6 Antidepressants and antipyretics are among the more commonly cited offenders (TABLE 1).⁴

TABLE 1
Medications that may cause sweating or flushing

Finding the right diagnosis requires thorough history & exam

With such a long differential diagnosis (TABLE 2),^4-6 night sweats should initially be evaluated with a thorough history and physical examination (according to a consensus opinion of various authors). If these don’t elicit possible causes, the appropriate next step in the work-up can vary. Some authors recommend multiple laboratory and imaging studies, while others advise against any routine tests. None of these approaches is evidence-based.

One reasonable algorithm recommends an initial work-up including a complete blood count, thyroid-stimulating hormone (TSH) and erythrocyte sedimentation rate (ESR) level, a purified protein derivative (PPD) and HIV test, and a chest x-ray.⁵ If the results are unrevealing, a trial of antireflux medication is recommended. If the patient does not improve, consider a diary of nocturnal temperatures to help discern the presence or absence of febrile pulses and further evaluate for suspected endocarditis or lymphoma.

TABLE 2
Differential diagnosis for night sweats

Evidence is scant for symptom relief

Very few clinical trials have directly studied symptomatic relief of night sweats. A large Cochrane meta-analysis found that oral hormone therapy—estrogens alone or estrogens with progesterone—reduced the frequency of night sweats associated with hot flashes among menopausal women by 75% when compared with placebo alone.⁷ Neither primrose oil nor foot reflexology proved effective.⁸

A cohort study found that 80% of the patients with frequent night sweats responded to antireflux therapy.³ One author suggests using therapies aimed at relieving hyperhydrosis.⁶ These include local treatment with aluminum chloride hexahydrate (Drysol), antiperspirants, scopolamine, or phenoxybenzamine hydrochloride (Dibenzyline).

Recommendations from others

A thorough literature search through Cochrane Database Systematic Reviews, AHRQ, National Guideline Clearing-house, and Medline did not yield any guidelines or consensus statements from other organizations or specialty groups on the evaluation or treatment of night sweats.

Evidence summary

Night sweats are a common complaint in the ambulatory primary care setting: Of 2267 patients in 1 cross-sectional study, 41% reported night sweats, defined as “sweating at night even when it isn’t excessively hot in your bedroom” within the previous month.¹ Because the peak prevalence in both men and women occurred in the group ages 41 to 55 years, there was concern that menopausal hot flashes were a confounding factor, at least for women. In a subsequent study of 795 patients older than 64 years, 10% still reported being bothered by night sweats.²

The more common causes are not widely studied

Few studies look at the causes of night sweats. Although they have been associated with tuberculosis, lymphoma, and HIV infection, these are not common causes of night sweats in outpatient care.

In the only study that specifically addressed the causes of night sweats in an ambulatory population, Reynolds³ interviewed 200 consecutive patients, 70% from a primary care practice and 30% from a gastroenterology practice. Of the 81 patients who reported having an episode of night sweats at least once a week, esophageal reflux and menopause were the most frequent causes.

Several authors agree that certain medications are frequently associated with night sweats, although the exact incidence is unknown due to a lack of published epidemiologic data.^4-6 Antidepressants and antipyretics are among the more commonly cited offenders (TABLE 1).⁴

TABLE 1
Medications that may cause sweating or flushing

Finding the right diagnosis requires thorough history & exam

With such a long differential diagnosis (TABLE 2),^4-6 night sweats should initially be evaluated with a thorough history and physical examination (according to a consensus opinion of various authors). If these don’t elicit possible causes, the appropriate next step in the work-up can vary. Some authors recommend multiple laboratory and imaging studies, while others advise against any routine tests. None of these approaches is evidence-based.

One reasonable algorithm recommends an initial work-up including a complete blood count, thyroid-stimulating hormone (TSH) and erythrocyte sedimentation rate (ESR) level, a purified protein derivative (PPD) and HIV test, and a chest x-ray.⁵ If the results are unrevealing, a trial of antireflux medication is recommended. If the patient does not improve, consider a diary of nocturnal temperatures to help discern the presence or absence of febrile pulses and further evaluate for suspected endocarditis or lymphoma.

TABLE 2
Differential diagnosis for night sweats

Evidence is scant for symptom relief

Very few clinical trials have directly studied symptomatic relief of night sweats. A large Cochrane meta-analysis found that oral hormone therapy—estrogens alone or estrogens with progesterone—reduced the frequency of night sweats associated with hot flashes among menopausal women by 75% when compared with placebo alone.⁷ Neither primrose oil nor foot reflexology proved effective.⁸

A cohort study found that 80% of the patients with frequent night sweats responded to antireflux therapy.³ One author suggests using therapies aimed at relieving hyperhydrosis.⁶ These include local treatment with aluminum chloride hexahydrate (Drysol), antiperspirants, scopolamine, or phenoxybenzamine hydrochloride (Dibenzyline).

Recommendations from others

A thorough literature search through Cochrane Database Systematic Reviews, AHRQ, National Guideline Clearing-house, and Medline did not yield any guidelines or consensus statements from other organizations or specialty groups on the evaluation or treatment of night sweats.