I'm in my mid-twenties and the strength of my morning erections vary. Should that be a cause for concern?
Each time you have an erection, you don't necessarily have the most intense one possible. It varies with things such as how strongly you are aroused and how fast your heart is pumping at the time. Nor is an erection held at peak strength for a long time. Your body needs to get fresh quantities of blood into the penis or it will begin to hurt.
When you awake in the morning, you are not necessarily at the peak phase of an erection at that moment in time, nor is each morning erection going to be at the same level of intensity. There will be mornings when you crawl out of bed and realize that you didn't have an erection this time. All of this is normal.
However, if you haven't had an erection in a while, say over a month, then there is a possibility that something is going wrong with your system. A lack of erections is one of the early warning signs of diabetes and heart disease. If you haven't had an erection in a while, it might be wise to see a doctor to have a general physical.