Short answer, it depends. I know, lousy answer, not what you wanted, but it’s true! Everyone is different. Now for the long answer; from all the combined experiences of multiple dry needlers, there is a common trend amongst most people who get dry needled. For almost everyone, the needle is not an issue. I use a very thin filiform needle that is so thin that most people don’t feel it. So, even if you are afraid of needles, it should not be an issue. In fact, many people have to ask if the needle is in, that’s how thin it is.
When inserting the needle, I go through the skin and into the muscle I am targeting, trying to hit a trigger point. When hitting a trigger point (of which there can be multiple) I get what is called a local twitch response (LTR). From what is known from scientific literature, it is thought to be a reflexive contraction of the muscle. That is actually a good thing, as it is a sign you are in the correct area. In fact, there is evidence to show that the LTR is associated with many positive effects related to healing and blood flow.
For some people, the sensation of the LTR is enough to catch them by surprise and cause a momentary gasp and heavy breathing. Typically, during the procedure, the needle is manipulated up and down to reach multiple trigger points. Even if you get used to the muscle jumping, it is quite an experience and most people say it just feels weird.
Another thing that happens is the reproduction of your usual pain, the one you came to therapy for. People with frequent headaches and get dry needling done in the sternocleidomastoid (SCM) muscle on the neck, might report having their headache. They might say that their typical thigh pain is reproduced when we needle the glutes. These are good things too, that means we are treating the source of your pain. This pain aggravation can last for about one hour before starting to decrease.
Some other people might report a release sensation and describe it as very pleasing similar to a deep tissue massage. This is quite common in the neck area where a lot of tension is carried.
Others might report nothing significant, but once they get up from the table they notice they can move much easier. Some athletes might jump right into training immediately after dry needling.
A few might actually feel some intense twinges and might yell and curse, but trust me, even they keep coming back and say it is very therapeutic for them.
Afterward:
The first hour you might get your usual pain and is going to be the most intense.
After that first hour, you will notice a decrease in intensity but will continue to be sore for the rest of the day.
By the next day, you will feel muscle soreness as if you had exercised.
This will dissipate and by then you should already be feeling much better.
In summary, dry needling is a different experience for everyone, it can be intense but it is always manageable. But most importantly, for the majority, it is a good experience that helps them on their journey to relieve pain and move better.