The managing director yells, curses, accuses you of lying, slams doors and issues emails full of false accusations and half-truths. Every day your stomach tightens up the second you get off the elevator onto your floor and it stays that way all day. You come home from work and snap at your spouse and your kids. Lately it’s hard to sleep.

You are miserable, but you can’t just quit, not in this job market. You are afraid to go to Human Resources because you think that will make things worse.

You are certainly suffering from a hostile work environment, but is it illegal? The answer depends on several factors:

Federal, state and city law all make it unlawful for an employer to maintain a hostile work environment based on an employee’s membership in a particular protected class — for example, because an employee is female, or African-American, or disabled or over 40. If the boss is an equal opportunity jerk, and treats everyone equally badly, it’s less likely that his behavior is unlawful.

What if your boss isn’t the problem, but it’s your co-workers who are behaving badly? If your co-workers are creating a hostile work environment based on your membership in a protected class, your employer may be responsible for their actions. Your employer is especially likely to be held accountable if it doesn’t maintain a procedure for complaining about unlawful harassment and/or if it fails to take prompt effective action after a complaint is made.

What if you complain to Human Resources and get fired because of your complaint? Federal, New York State and New York City law all prohibit retaliation against a person because she or he complains of unlawful discrimination, provided that the employee had a reasonable basis to believe that she or he was being discriminated against. Most employers have complaint procedures. If you get fired or otherwise retaliated against because of your complaint, you may have a separate claim against the employer, for retaliation.

The bottom line: When a work environment is “hostile” in the legal sense, you may have a legal claim, and taking prompt action may be crucial.