Character health issues can be increased in Path of exile currency several ways by:

Increasing the personality level - the character will benefit 12 health points. Exotic skills - some abilities on the ability tree allow you increase the proportion of health issues or to get points. Increasing the Strength feature - the health point swimming is increased by every 10 points.

Equipment - a bonus is offered by a great deal of items to Strength parameter or health issues.

Indirect - because it does not impact the number of health issues - a way to improve the character's endurance would be to boost its defensive parameters - i.e. defense, dodging and immunity to certain components. This won't increase the amount of cheap Path of exile currency health issues, but you will lose less with each blow that is received.