Why tiredness and breathlessness with numbness in the feet matters
Tiredness on its own is one of the vaguest complaints in medicine. Tiredness with breathlessness suggests anaemia or heart and lung disease; add numb feet and unsteadiness, and the two complaints may share one cause. Linking them is the skill this case asks for.
What to ask in the history
- How long, and how the tiredness and breathlessness have progressed
- The numbness: where it started, whether it is spreading, whether she is unsteady, worse in the dark
- Memory, mood or concentration changes
- Diet: vegetarian or vegan, how much she eats
- Bowel symptoms, weight loss, previous stomach or bowel surgery
- Bleeding: heavy periods (if still menstruating), black stools, blood in stools
- Alcohol
- Medicines: metformin, proton pump inhibitors
- Other autoimmune conditions in her or her family: thyroid disease, vitiligo, diabetes
Red flags
- Rapidly worsening weakness, falls or unsteadiness
- Confusion or memory loss
- Breathlessness at rest or chest pain
- Weight loss or blood in the stool
- Low counts in more than one cell line (anaemia with low platelets or white cells)
What to examine
- Pallor, a slightly yellow tinge, a smooth sore tongue, mouth ulcers
- Vitiligo, thyroid swelling
- Pulse, a flow murmur, signs of heart failure
- Neurological examination of the legs: tone, power, reflexes, plantar responses
- Vibration and joint position sense, and Romberg's test
- Gait
First investigations
- Full blood count with MCV, and a blood film
- Reticulocyte count
- Vitamin B12, folate and ferritin
- Thyroid function
- Blood glucose or HbA1c
- Renal and liver function, LDH and bilirubin
Differential diagnosis of tiredness and breathlessness with numbness in the feet
Grouped, not ranked. Which one fits this patient is for you to work out in the case.
Nutritional and absorptive
- Vitamin B12 deficiency (pernicious anaemia, diet, malabsorption)
- Folate deficiency
- Iron deficiency
- Coeliac disease
Endocrine and metabolic
- Hypothyroidism
- Diabetes with peripheral neuropathy
- Chronic kidney disease
Toxic
- Alcohol-related neuropathy and macrocytosis
- Medicines
Marrow and malignancy
- Myelodysplasia
- Myeloma
- Other malignancy
Common mistakes
- Treating 'tiredness' as age or stress without a blood count.
- Testing the sensation in the feet with a pin only. Vibration and position sense pick up a different set of nerve problems.
- Starting folic acid on its own before vitamin B12 deficiency is excluded.