I just want to ask because my contact is all ready...

We would like to inform you that if you are an expat in UAE and your work visa is expired, and you keep on working with the same sponsor, then note that if the work contract is not renewed automatically, then you will have fines for the overstay. So if you want to leave the country you have to settle the fines and get NOC from the sponsor, and you have to file resignation from the work if the contract is renewed automatically.
The law regulates that matter in the below articles:
Article (113)
An employment contract shall terminate in any of the following cases:
1. By mutual agreement of the Parties, provided that the worker's consent is given in writing;
2. Upon expiry of its term, unless it has been expressly or implicitly extended according to the provisions of this Law;
3. For the convenience of either party to an indefinite term contract, provided that the provisions of this Law concerning the notice and the valid grounds of termination without arbitrariness are adhered to.
Article (116):
Where a contract is revoked by the worker for reasons other than those stipulated in Article (121), he shall be required to compensate the employer for any damage the latter sustains as a result, provided that the amount of compensation shall not exceed half a month wage for three months or for the remaining period of the contract, whichever is shorter, unless otherwise stipulated in the contract.
Article (117):
1. Either the employer or the worker may terminate an indefinite term contract for a valid reason at any time following its conclusion, by giving the other party a notice in writing at least 30 days prior to termination.
2. For the daily-paid workers, the notice period shall be as follows:
• One week: if the worker has been employed for more than six months but less than one year.
• Two weeks: if the worker has been employed for not less than one year.
One month: if the worker has been employed for not less than five years.
Article (118):
A contract shall subsist throughout the notice period referred to in the preceding Article and shall terminate only on expiry of that period. The worker shall be entitled in respect of the notice period to full pay, calculated on the basis of his last wage, and shall continue to perform his duties during that period if the employer so requests. The Parties may not agree to waive the notice requirement or to reduce the notice period; however, they may agree to extend the period.
Article (119):
If either the employer or the worker reduces the period of, or fails to serve a notice of termination on the other, the forbearing party shall pay the other a “compensation in lieu of notice”, irrespective of whether or not the other party has sustained damage as a result of such failure or shorter notice. The said compensation shall be equal to the worker's wage in respect of the entire or reduced period of notice. Compensation in lieu of notice shall be calculated on the basis of the last wage received, in the case of monthly, weekly, daily and hourly paid workers, and on the basis of the average daily wage referred to in Article 57 of this Law in the case of those paid on piecemeal.
Note that after resignation and accepting it that requires NOC and cancelling the visa by the sponsor or any other representative.

Before renew the visa and the work contract, you had better notify the employer that you don’t want to renew. But if you are sick and you can’t work due to the pain, then you can apply a letter to present you to a medical commission to report your health status. According to that report a decision will be made about the termination according to the law.

Therefore, you can go to the labor office and file a complaint and explain the details and ask to present you to the medical committee, if it is proved that you can’t work, then they will contact the sponsor to terminate you to leave the country.