The amount you can contribute to your HSA account
depends on what type of High Deductible Health Plan (HDHP) you have.
"For 2017, if you have self-only HDHP coverage, you
can contribute
up to $3,400. If you have family HDHP coverage, you can contribute up to $6,750."
This
information can be found
here
on page 4 of 22. Look at Limit on Contributions.
However,
you can pay medical expenses for your spouse with distributions from your HSA.
"Qualified medical expenses are those incurred by the following persons.
1. You and your spouse.
2. All dependents you claim on your tax return.
3. Any person you could have claimed as a dependent on your return except that:
a. The person filed a joint return,
b. The person had gross income of $4,050 or more,
or
c. You, or your spouse if filing jointly, could be claimed as a dependent on someone else's 2017 return."
This information can be found at the same link as above on page 8 of 22.