Primary Focal Hyperhidrosis — Bilateral Palm, Sole, Axilla Sweating
Symmetric excess sweating at classic focal sites defines primary hyperhidrosis.
- 3: Typical sites (Palms, soles, axillae)
- Bilateral: Symmetry (Hallmark clue)
- ~3%: Prevalence (General population)
- Absent: Sleep sweating (Usually stops at night)
Recognizing the focal pattern
Sweating localizes to hands, feet, and underarms symmetrically.
Onset Age and Family History as Diagnostic Clues
Early onset plus family history points strongly toward primary disease.
- <25y: Typical onset (Childhood/adolescence)
- ~30-50%: Family history (Positive in primary cases)
- No: Night sweats (Suggests primary)
- Stable: Course (Chronic, unchanging)
Why age and heredity matter
Young onset with relatives affected favors a primary focal cause.
Generalized Hyperhidrosis — Whole-Body Diffuse Sweating
Sweating involves the entire body surface rather than isolated sites.
- Diffuse: Distribution (Trunk, face, limbs)
- Common: Night sweats (Often present)
- Adult: Onset (Often later in life)
- Variable: Symmetry (Not always bilateral)
Whole-body involvement
Diffuse sweating pattern differs sharply from focal hotspots.
Secondary Causes — Hyperthyroidism, Menopause, Infection
Systemic conditions like thyroid disease often drive generalized sweating.
- Common: Hyperthyroidism (Heat intolerance, tremor)
- Common: Menopause (Hot flashes, night sweats)
- Consider: Infection/TB (Fever, weight loss)
- Rare: Malignancy (Lymphoma flag)
Screening for systemic disease
Adult-onset generalized sweating warrants a search for underlying cause.
Red flags: weight loss, fever, night sweats need urgent workup.
Diagnostic Workup — Separating Primary from Secondary
Targeted history, exam, and labs confirm the underlying category.
- TSH: Key labs (Plus glucose, CBC)
- CXR: Imaging (If infection suspected)
- Sites: Exam focus (Distribution mapping)
- 2 paths: Outcome (Primary vs secondary)
Building the diagnosis
Combine pattern, onset, and labs to reach a final differential.