• Skin temperature redistribution (distal extremities are colder; trunk is warmer)
  • Increased skin temperature inhomogeneity under emotional stress (up to reversible red and white skin blotches)
  • Low blood pressure; blood pressure drops especially at night
  • Low body mass index
  • Prolonged flow cessation after cold provocation, Reduced blood flow velocity in the Nailfold capillaroscopy
  • Silent myocardial ischemia
  • Altered activity of the autonomic nervous system (beat-to-beat variation)
  • Slightly elevated plasma endothelin-1 level
  • Altered gene expression (measured in lymphocytes)


  • Reduced capacity to autoregulate ocular blood flow
  • Correlation between the optic nerve head and peripheral blood flow
  • Increased stiffness of retinal vessels
  • Higher spatial irregularities in retinal vessels
  • Reduced neurovascular coupling (endotheliopathy)
  • Increased retinal venous pressure
  • Increased blood flow resistance in retroocular vessels

These signs listed above are often seen in Flammer syndrome, but not all are obligatory.
These signs are more or less strongly pronounced.

As an example of a sign we depict here the result of a 24-h blood pressure monitoring. Right: 24-hours- blood pressure in a subject with Flammer syndrome (red) and without Flammer syndrome (grey).