It seems that since I’ve been practicing the handstand/headstand (using full arm support with as little as possible weight on soft spot of the head) I’ve noticed my neck cracks occasionally when I turn my head. Is this something I should be concerned about? Has anyone noticed that type of thing?
Would I be concerned if my neck joints were cracking as a result of headstand? You bet ya! The neck protects some of the most important nerves in your body and you don’t want to compromise it’s integrity. It wasn’t really built for carrying (part of) your body weight - your feet are meant for that. Although headstand can be very beneficial, it can also be harmful. Accidents are likely to occur while going into or out of the pose. Please align yourself with yoga (non-violence) and stop doing headstand until you consult your teacher for personal advice. In the meantime, be aware that some of headstand’s benefits can also be obtained from other inverted poses like downward dog, supported shoulderstand, or shoulderstand (with a pad under your shoulders to protect your neck).
I find the OP confusing Renie.
Are you asking about Sirsasana (headstand) in which the head does contact the ground or are you asking about Adho Mukha Vrksasana (handstand) where the head is not in contact with the ground?
Is the “cracking” of the neck something you are experiencing in daily life, just after your practice, during the pose?
Here is an applied answer rather than a complete anatomical or kinesiological one.
The vertebra in the spine can subluxate or move out of their inherently appropriate position. A subluxated vertebra is incredibly common and our spine is self adjusting all day long. (This is NOT a slipped or bulging disc.) The spine is never static - though some would like to believe otherwise. That is their choice. The alignment of the vertebra is, in part, the basis of chiropractic care.
In some instances a re-alignment of the vertebra which may be accompanied by a cracking noise (though not necessarily) is completely in order and relieves pressure on the nervous system. In situations where the cracking is constant or becomes an addition for “feeling well” then something else is likely going on.
As is pointed out, the cervical spine, or neck is one of the three weakest links in the body in addition to the knees and lowerback. So care should be used. However moving concern to the level of worry or freak out can only be detrimental as the physical body reflects the thoughts.
For my students I would want to determine the nature their practice and make adjustments from there. If you do not have a teacher who can do so then consider finding one. That teacher should provide you instruction on finding and engaging the muscle critical in sirsaasana, adho mukha vrksasana, and pincha mayurasana - the serratus anterior. If you opt to handle this on your own please avoid weight-bearing on the head and see if that changes the situation. If you are akin to chiropractic perhaps now would be a time for a visit.
[quote=InnerAthlete;15431]I find the OP confusing Renie.
Are you asking about Sirsasana (headstand) in which the head does contact the ground or are you asking about Adho Mukha Vrksasana (handstand) where the head is not in contact with the ground?
Is the “cracking” of the neck something you are experiencing in daily life, just after your practice, during the pose?
For my students I would want to determine the nature their practice and make adjustments from there. If you do not have a teacher who can do so then consider finding one. That teacher should provide you instruction on finding and engaging the muscle critical in sirsaasana, adho mukha vrksasana, and pincha mayurasana - the serratus anterior. If you opt to handle this on your own please avoid weight-bearing on the head and see if that changes the situation. If you are akin to chiropractic perhaps now would be a time for a visit.[/quote]
Thank you so much for the informative comments. I do the Sirsasana, where there is minimal weight on the soft spot of the head, with the objective being to eventually lift head off the ground and bear all weight on the arms. I’ve been instructed by yoga teachers on the proper way to do this, with emphasis on very little weight on the head or neck.
The cracking is painless and may only occur once a day, and only when I turn my head. Sometimes it happens a few times a day, but never while doing yoga. I practice yoga about 5 hours a week.
I have scoliosis, though not too serious, according to a chiropractor. Hopefully, I’ve answered your questions.
Thank you Renie. That is more clear.
I get cracking lately, as I have posted. I don’t turn my head and as B.K.S. Iyengar writes in Light on Yoga, I try to bear the weight on my head with arms et al for balancing. I feel that my alignment is good-it feels good and I have no residual problems. I enjoyed Innerathlete’s reassurances. I’d like to know what asana you are doing that turns the head whilst in sirsasana .
my neck gets a good crack every now and then, I can often feel when it needs it and if the muscles around the neck and trapeze are relaxed enough it happens very easily leaving me with a pleasant feeling of freedom in that area 
Sorry Renie, I reread your post and saw my mistake about turning the head " never while doing yoga " Namaste