After you get the mask that turns you into a sandwraith can you get health..

Hmmm, don't really know the numbering system of Life Upgrades, so I'll explain them all.

1) Sacrifical Altar - behind statue; obtained anytime
2) Fortress Entrance - the grill, easier to get into when you slow down time; obtained anytime
3) Central Hall - point the lever towards Hourglass Chamber, jump down rock formations; obtained anytime
4) Gardens - place with the drawbridge and the pressure switch, where you fight the Crow Master, off the balcony edge; area blocked off by gate, I assume that the last time you can get this one is during 'A Throne and a mask', just before you go through the breakable wall behind the throne (it caves in behind you)
5) Garden Waterworks - small room where you activate main lever for the moat's water; obtained anytime
6) Activation Room - place where Brute is throwing exploding monsters; first opportunity to get this Life Upgrade is to get the Brute to explode the wall during 'Clockworks and Gears', second time is after you get the Scorpion Sword (beginning of 'A Throne and a mask'), head for the top of the Mechanical Tower, then to the top of the Mechanical Pit, then travel to the present, go down the Mechanical Pit and then up through the cog mechanism, then through the Activation Room to the past. Also blocked by a gate (top of Mechanical Pit), so last time to get it is also before the end of 'A Throne and a mask'
7) Prison/Library - prison area before library, after fighting Brute, behind breakable wall; obtained during 'A Throne and a Mask', OR during 'Mirrored Fates'. Once you go through the Library's ledge-pressurized door, it's too late
8) Library - square hole in wall, near octagonal beam sets; obtained during 'A Throne and a Mask'. Near the end of the game, you can retrace your steps by going to the base of the Mechanical Tower and through the wooden room (the one where the door was exploded by the bomb creature)
9) Southern Passage - area from 'Chasing The Girl In Black', corner balcony with breakable gate; obtained anytime

By the way, you get turned into the Sand Wraith during 'A Second Chance', which is after 'A Throne and a mask' and before 'Mirrored Fates'.

You have to get some upgrades BEFORE you get the Mask. Once you have the mask, several routes get closed. Once you have the Scorpion Sword, make sure that you get any you've missed. The same goes for Artwork.