▁head aches ▁accompanied ▁by ▁n ause a ▁or ▁vom iting . ▁There ▁may ▁be ▁an ▁a ura ▁( visual ▁sympt oms , ▁num b ness ▁or ▁t ing ling ) ▁ 3 0 – 6 0 ▁minutes ▁before ▁the ▁head ache , ▁warning ▁the ▁person ▁of ▁a ▁head ache . ▁Mig ra ines ▁may ▁also ▁not ▁have ▁a uras . ▁T ension ▁type ▁head aches ▁usually ▁have ▁bil ater al ▁" band like " ▁pressure ▁on ▁both ▁sides ▁of ▁the ▁head ▁usually ▁without ▁n ause a ▁or ▁vom iting . ▁However , ▁some ▁sympt oms ▁from ▁both ▁head ache ▁groups ▁may ▁overlap . ▁It ▁is ▁important ▁to ▁distinguish ▁between ▁the ▁two ▁because ▁the ▁treat ments ▁are ▁different . ▁ ▁The ▁m nem onic ▁' PO UND ' ▁helps ▁distinguish ▁between ▁mig ra ines ▁and ▁t ension ▁type ▁head aches . ▁PO UND ▁stands ▁for ▁P uls atile ▁quality , ▁ 4 – 7 2 ▁hours ▁in ▁length , ▁Un il ater al ▁location , ▁N ause a ▁or ▁vom iting , ▁Dis abling ▁intensity . ▁One ▁review ▁article ▁found ▁that ▁if ▁ 4 – 5 ▁of ▁the ▁PO UND ▁characteristics ▁are ▁present , ▁mig raine ▁is ▁ 2 4 ▁times ▁as ▁likely ▁a ▁diagn osis ▁than ▁t ension ▁type ▁head ache ▁( lik elihood ▁ratio ▁ 2 4 ). ▁If ▁ 3 ▁characteristics ▁of ▁PO UND ▁are ▁present , ▁mig raine ▁is ▁ 3 ▁times ▁more ▁likely ▁a ▁diagn osis ▁than ▁t ension ▁type ▁head ache ▁( lik elihood ▁ratio ▁ 3 ).