Night sweats

Borders Ref Help Toolkit
NHS Borders

Definition

Significant generalised night time sweating that soaks bedclothes or bedding.

Night sweats are a fairly common symptom and the majority of patients do not have an underlying haematological malignancy.

Medical causes are very varied and include:

  • infection
  • menopause
  • anxiety
  • endocrine causes:
    • hyperthyroidism
    • nocturnal hypoglycaemia in diabetics
    • acromegaly
    • phaeochromocytoma
  • obstructive sleep apnoea
  • connective tissue disorders
  • neurological:
    • parkinsonism
    • neuropathies
  • medications:
    • antipsychotics
    • SSRIs
    • hormonal agents such as Tamoxifen and GnRH agonists
  •  alcohol excess or withdrawal
  • drug abuse (including cannabis use / withdrawal)
  • gastritis
  • haematological malignancies.

Who to refer, who not to refer, how to refer

Who to refer:

Only refer patients with genuinely drenching sweats and any of:

  • significant additional systemic symptoms: unexplained weight loss >10%, fever or alcohol-induced pain
  • associated nodal enlargement and / or splenomegaly
  • abnormal FBC

Who not to refer:

  • Night sweats only, otherwise well with normal FBC – these patients should be investigated in primary care as are unlikely to have lymphoma
  • Patients with sweats which are not genuinely drenching

How to refer:

SCI Gateway to the Department of Haematology, BGH

Primary care management

Primary care investigations

  • FBC
  • Blood film
  • CRP
  • Thyroid function tests
  • Lactate dehydrogenase (LDH)
  • HIV serology (ie antigen and antibody test)
  • Quantitative immunoglobulins and serum electrophoresis 
  • Gonadotrophins and oestradiol where appropriate
  • CXR

Editorial Information

Last reviewed: 06/05/2025

Next review date: 06/05/2027

Author(s): Charlotte Robertson.