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.
- Gait speed, Short Physical Performance Battery or Timed Up and Go helps grade physical performance and rehabilitation need.
- Always seek acute illness, focal neurology, pain, nutrition, endocrine, inflammatory, medicine and organ-disease causes rather than assigning weakness to age.
- First-line treatment is progressive resistance exercise plus balance and functional task practice, delivered often enough and progressed to produce adaptation.
- Aim for adequate energy and usually about 1.0 to 1.2 g protein/kg/day in healthy older adults, with higher individualised targets during illness and lower or adjusted targets in relevant kidney or metabolic disease.
- Distribute protein across meals and involve dietetics when intake, weight loss, dysphagia, renal disease or refeeding risk complicates advice.
- There is no routinely licensed medicine that replaces exercise and nutrition for sarcopenia.
- Prevent hospital-associated deconditioning by mobilising, dressing, toileting, eating out of bed and removing unnecessary tethers from the first safe day.
Key red flags
Sudden unilateral weakness, speech change or ataxia is stroke until urgently assessed.
Bulbar symptoms, weak cough, respiratory decline or rapidly progressive symmetrical weakness requires emergency neuromuscular review.
Severe muscle pain, dark urine, immobility or statin interaction with CK rise suggests rhabdomyolysis.
Fever, delirium, hypoxia or abrupt ADL loss may be the principal presentation of infection in an older adult.
Unintentional weight loss, dysphagia, anaemia, lymphadenopathy or night sweats requires malignancy and systemic-disease assessment.
Unsafe swallowing, intake below needs, dehydration or refeeding risk requires prompt dietetic and medical management.
Rapid proximal weakness, pain, rash or dark urine with CK concern is not simple age-related sarcopenia.
Dysphagia, weak cough or respiratory decline requires urgent neuromuscular and airway assessment.
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.
- Confirm muscle quantity by DXA or validated bioimpedance when it will change classification or care.