Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic features (SUNA) are described, although SUNA is rarely reported. The phenotype of SUNCT and SUNA was characterized from a large series of patients (43 SUNCT, 9 SUNA). Three attack types were identified: stabs, groups of stabs and saw-tooth attacks. The mean duration of stabs was 58 s (1-600 s); stab groups, 396 s (10-1200 s); and saw-tooth, 1160 s (5-12 000s). The attack frequency was a mean of 59 attacks/day (2-600), and this depended largely on the type of attack. The pain was orbital, supraorbital or temporal in 38 (88%) SUNCT and 7 (78%) SUNA, and also occurred in the retro-orbital region, side, top, back of head, second and third trigeminal divisions, teeth, neck and ear. All SUNCT patients had conjunctival injection and tearing. Two SUNA patients had conjunctival injection, four had tearing, but none had both. Other cranial autonomic symptoms included nasal blockage, rhinorrhoea, eyelid oedema, facial sweating/flushing and ear flushing. Cutaneous stimuli triggered attacks in 74% of SUNCT but only in 22% of SUNA patients. The majority (95% SUNCT and 89% SUNA) had no refractory period between attacks. For SUNCT 58% and for SUNA 56% of patients were agitated with the attacks. We propose a new set of diagnostic criteria for these syndromes to better encompass the clinical presentations and which include a wider range of attack length, wider trigeminal pain distribution, cutaneous triggering and lack of refractory period.