You can refer to problems or difficulties as trouble .

If you say that one aspect of a situation is the trouble, you mean that it is the aspect which is causing problems or making the situation unsatisfactory.

Your troubles are the things that you are worried about.

If you have kidney trouble or back trouble, for example, there is something wrong with your kidneys or your back.

If there is trouble somewhere, especially in a public place, there is fighting or rioting there.

If you tell someone that it is no trouble to do something for them, you are saying politely that you can or will do it, because it is easy or convenient for you.

If you say that a person or animal is no trouble, you mean that they are very easy to look after.

If something troubles you, it makes you feel rather worried.

If a part of your body troubles you, it causes you physical pain or discomfort.

If you say that someone does not trouble to do something, you are critical of them because they do not behave in the way that they should do, and you think that this would require very little effort.

You use trouble in expressions such as I'm sorry to trouble you when you are apologizing to someone for disturbing them in order to ask them something.

If someone is in trouble, they are in a situation in which a person in authority is angry with them or is likely to punish them because they have done something wrong.

If you take the trouble to do something, you do something which requires a small amount of additional effort.

If you say that someone or something is more trouble than they are worth, you mean that they cause you a lot of problems or take a lot of time and effort and you do not achieve or gain very much in return.