ok here goes...
I'm a mermaid and here are the side affects:

no.1: legs changing colour/getting tingly ichy یا achey
no.2: nauisa ( maybe vomiting)
no.3: difficulty breathing
no.4: coughing fits when in water
no.5: being able to breath in water/ hold your breath longer
no.6: random anger
no.7:scales appearing on your skin
no.8: gills appearing on your neck یا under your armpits
no.9: legs sticking together یا wanting to be together
no.10: legs crossing سے طرف کی themselves
no.11: constant thirst after drinking lots of fluid
no.12: headaches
no.13: wanting to touch یا be in water

THESE ARE NOT NESECARY ONLY SOME PEOPLE HAVE THEM!!
p.s check out www.lifewithatail.co.uk for مزید tips

see ya!