Loud or abnormal noises
Although the amount of noise that a garage door makes during operation will vary from door to door, excessive noise can be a sign of wear or damage. If you find that the noise is coming from your garage door opener, it can indicate that the motor is under excessive stress. There are a few possible causes for this, some of which are more serious than others.
One possible cause is a damaged or broken garage door spring. Garage door springs act as a counter-force, bearing a significant portion of the garage door's weight to reduce the load on the opener. When a garage door spring is broken or damaged, the garage door motor is forced to work harder to lift the extra load that is no longer being supported. This can easily lead to further damage and should be addressed immediately by a professional. In addition, a garage door spring breaking is a safety risk that can lead to serious injury or, in some cases, death.
Less serious reasons why your garage door opener may be under stress include poor lubrication, damaged/worn parts and obstructions. These should also be repaired as soon as possible but are usually far less dangerous than a damaged spring.
The bottom line is if your garage door or garage door opener are making abnormal or excessive noise during operation, the best course of action is to contact a professional for garage door repairs.

Irregular movement
The way that your garage door moves during operation can also be an indication of whether or not you need repairs. When everything is working properly, your garage door should open and close in a fluid motion, moving at the same speed in both directions and requiring the same amount of effort.
If you find that your garage door moves noticeably faster when closing than opening, this can indicate that your garage door opener is struggling with the weight of your garage door. As mentioned above, garage door springs are responsible for regulating this, making them the most likely cause. Again, this can be a serious risk and should be dealt with immediately.
If your garage door is not moving smoothly, there are several reasons why this could be. Firstly, it could be due to friction. If parts of your garage door are rusted or not adequately lubricated, they may be getting stuck momentarily when the door is opening or closing. Secondly, there may be something obstructing your garage door during operation. If the door or one of its parts gets caught on something, it may interrupt the operation, making it appear less fluid. Lastly, one or several parts of the garage door or garage door opener may be worn. This can be hard to identify and should be checked by a professional.
As with most things, several things could affect the movement of your garage door. In most cases, whether you can identify a specific cause or not, the best thing to do is to have your garage door inspected by a qualified professional. There are things that are easy to fix by yourself, but these should only be done with the appropriate experience, skills and tools.
Obvious visual indicators
In addition to unusual movement and noises, it pays to actively inspect the visible parts of your garage door and garage door opener. This doesn't have to take long, but actively looking at your garage door and garage door opener allows you to spot any obvious signs of damage that may have gone unnoticed. This can be anything from rust to broken or missing parts. Anything that is obviously worn, broken, missing or generally out of place should be taken note of and addressed as soon as possible. Although it's simple, it's because of this that there's no reason to miss anything that would be obvious at a glance.
If you need garage door repairs, Homeline is the place to go.