Let us say that at your place of work you are having issues with someone making unwelcome advances. This person is highly placed in the company, and you are afraid to say anything because she has the power to demote you, or even fire you.
You are not sure if you should discuss the matter with someone in Human Resources. Can they help? Will they keep your confidence? Are there other options?
The stance they take
The HR department is part of the company, just like the department where you work, and the personnel there usually report to upper management. If you have a complaint that is not illegal--for instance, if the person who is bothering you is simply being rude--HR may be able to help, but that might depend on just how highly placed this person is. If you are talking about a senior manager, help may be forthcoming, but if the perpetrator is a senior vice president, HR might not pursue the matter of rudeness on your behalf.
Matters HR must pursue
On the other hand, if you tell HR that this highly placed person is sexually harassing you, they are legally required to investigate the matter. They will probably ask you to lodge a formal complaint in writing. Keep in mind that sexual harassment is not the sort of subject you can talk about off the record. The people who work in Human Resources are not required to keep information confidential, so you will want to think carefully about what you want to say to them.
Depending on the situation that has developed, you may feel more comfortable reaching out for legal counsel rather than speaking to someone in HR. An attorney experienced with cases involving workplace discrimination and various kinds of harassment will tell you that you do not have to put up with behavior that is bringing stress and fear into your working life. You have protections under the law, and your attorney will ensure that they are implemented on your behalf.