I'm often surprised to find out that so many people don't consider misdemeanor offenses to be a "big deal." Obviously, they are not as serious as felonies and cannot result in any state prison time. But being charged with a misdemeanor can still have some life-altering consequences.
Misdemeanors are crimes, and being charged with a misdemeanor means that you were arrested. Even if the officer issues you a written promise to appear (PTA), it is still an arrest (albeit an arrest on paper).
Misdemeanors will remain on your criminal record if you do not seal or expunge.
Misdemeanor convictions (adjudications) can never be sealed or expunged and will prevent you from ever sealing or expunging another arrest.
You can go to jail for a misdemeanor. First-degree misdemeanors carry a maximum of one year in jail, while second-degree misdemeanors carry a maximum of 60 days.
A number of misdemeanors can be used to "enhance" you if you get arrested for them enough times. Multiple convictions for offenses like prostitution, petit theft, and battery can be used to charge you with a felony later on. In other words, a misdemeanor can become a felony if you have enough priors (such as prior petit theft convictions, prostitution convictions, and battery convictions).
DUI - arguably one of the most serious misdemeanor offenses - carries a mandatory conviction. You can also be charged with a felony on your third DUI. Same for driving while license suspended (DWLS).
If you are convicted (adjudicated) of possession of marijuana, you will lose your driver's license for two years.
Pleading guilty or no contest to a misdemeanor domestic violence charge will result in your inability to obtain a concealed weapons permit in Florida. It is also a charge that is ineligible to be sealed.
Even if you complete a diversion program, such as Pretrial Diversion (PTD) or the Misdemeanor Diversion Program (MDP), you will still have an arrest record. You must expunge in order to have a clean criminal record.
If you are unable to expunge, a misdemeanor arrest on your record (even if the charge was dropped) can result in denial of employment. Also, property management companies and homeowners' associations can reject your application with a prior arrest.
A misdemeanor conviction (and for immigration purposes a withhold of adjudication is considered a conviction) can result in your deportation if you are not a U.S. citizen.
Needless to say, any arrest is a big deal. Even if you are not facing substantial jail time, the consequences of a misdemeanor can destroy everything that you have worked for - your reputation, your job, your education, your desire to find a decent place to live.
My advice - don't take chances. If you are charged with a misdemeanor, seek professional assistance from a criminal defense attorney.