Synopsis
Recognise clinically important loss of strength and physical reserve, separate chronic sarcopenia from acute disease and focal neurology, and rebuild function through progressive resistance, activity, nutrition and cause treatment.
- Sarcopenia is a muscle disease defined by low strength, with low muscle quantity or quality confirming diagnosis and low physical performance indicating severe disease.
- SARC-F is a pragmatic case-finding questionnaire, not a confirmatory test; a low score can miss disease when clinical suspicion is high.
- First-line assessment measures strength with handgrip or five-chair-rise performance, then muscle quantity by DXA or validated bioimpedance where confirmation changes care.
Key red flags
Sudden unilateral weakness, speech change or ataxia is stroke until urgently assessed.
Rapid proximal weakness, pain, rash or dark urine with CK concern is not simple age-related sarcopenia.
Investigation priorities
Separate chronic muscle loss from acute deterioration.
Identify low muscle strength first line.
Management branches
Persistent weakness or functional decline is not explained by an emergency.
- Establish trajectory and baseline and exclude acute focal, metabolic, infectious and neuromuscular disease.
- Measure grip or chair-rise strength and assess gait or SPPB with protocol recorded.