Redness and itchiness are side effects of Minoxidil. See link
...the side effects of minoxidil can include scalp irritation, itchiness and dryness.
Imagine your hair is like grass. You mow the lawn and after a while it grows back up from the ground. Hair grows from the scalp and when you cut it you are cutting off old hair. Hair grows an inch a month.
The more often you cut your hair, the quicker it grows back. Therefore, since we cut the hair on our head so often, it grows the fastest.
The Scalp is the area around the top of the head where your head hair typically grows. This excludes eye brow and facial hair that also grows on the head.
Nits? Is that an answer or a question. There could be a hundred causes but the most common causes are oily scalp, not clean, dry scalp, dandruff. The list goes on and on. If you can;t seem to get it under control, you should see a dermatologist.
it grows from the scalp
It can in extreme cases. If you are male it might be male pattern baldness. Best thing to do is to go to your doctor to see why your scalp is itchy.
the hair grows out of a root which is inside your scalp.
Human scalp hair normally grows at about 0.5 inches a month.
It could very well be dandruff.
Does it feel hot or itchy? It may be because dying your hair will dry out your scalp. If that is your case try doing some deep conditioning such has coconut oil on your scalp.
Hair all grows at the same speed.
I have had a madly itchy scalp for the last 6 weeks and I am up to week 12 week of my pregnancy. I feel like pulling my hair out... I suggest get a pregnancy test quick!