The following is a guide for the health items and other useful finds, like Pawnitems, money... in Tomb Raider: The Angel of Darkness. (These are the ones marked green in the walkthrough.)

Health Items

Keep an eye on your energy bar, the red bar at the top left corner. If Lara runs out of energy, she dies. But you can prevent this by taking health items. Check out the following list to find out which item is the right one for the current situation. You can pick these items in the inventory (press Select on the PS2 or Tab on the PC), in the health sub menu by selecting the item.

Chocolate Bar

By eating a chocolate bar Lara will regain 10% of her strength. This should be taken, when you want to regain your full strenght, after a minor injury.
"Energy boost. Restores health 10%"

Health Pills

The Health Pills will return 20% of Lara's energy.
"Stamina boost. Restores health 20%"

Health Bandages

Health Bandages as well as Small Medipacks are the perfect medication during a tough fight. They return 40% of Lara's energy.
"Prevents bleeding. Restores health 40%"

Small Medipack

Small Medipacks, like Health Bandages, are the perfect medication during a tough fight. Lara regains 60% of her strength.
"Contains limited medication. Restores health 60%."

Large Health Pack

A Large Health Pack will restore the full energy bar, so you should not use it unless you are almost dead.
"Extensive medication. Restores full health 100%."

Pawnitems

All these pickups can be exchanged for money in Rennes Pawnshop. Make sure you visit him before you get through the graveyard towards Bouchard's Hideout.

Antique Dubloons

Valuable item.
Rennes will give you 20 € for each piece.