Can CT head scan damage thyroid?

[Aquapuss]

Having had a head injury two weeks ago where I lost consciousness briefly, I was seen by A&E doctor who gave me standard head injury advice but no scan. Have had symptoms of fullness in head, particularly ears which feel blocked ( could be excess wax as I get this), also headaches, unable to look at screens for long, fatigue etc so my GP referred me for CT scan of head, but am worried that radiation could make thyroid worse, any advice on this would be great.

I have underactive thyroid, had dose increased to 150mcg over a year ago, since then have had recurrent goitre, feeling of lump in throat, hoarse voice especially in morning and dry skin, also two stone weight gain since increase in dose ( could also be related to less activity as working from home for past year but try to walk often and eat less than previously when out and about travelling with work) Also take Vit B complex ( private testing showed low folate), Vit D spray with K2 and recently started on magnesium supplement after reading about this on here. My head injury symptoms are improving so not sure if scan is necessary? But on the other hand, if there is any lasting damage/bleeding, it would be best to have it. Is there a risk of scan further harming my thyroid gland? Have also had higher radiation than most people due to having had breast cancer six years ago

[humanbean]

You can ask for a thyroid shield before getting your CT scan or any X-Rays.

MRIs and ultrasound scans are not dangerous, so no thyroid shield is necessary for those.

[Murphysmum in reply to humanbean]

So x rays are? I’ve often wondered this as I had A LOT of x rays as a child. Maybe that combined with my auto immune genetic traits made me a dead cert for where I am now 🙄

[Aquapuss in reply to Murphysmum]

All xrays, CT scans have radiation, amount varies in terms of effective dose depending on which part of body is scanned eg dental xrays have v small dose compared to abdominal x ray. Radiation is cumulative so over a lifetime can add up to a lot, its one reason they avoid xrays on children now much more

[Aquapuss in reply to humanbean]

Thanks! Its funny though, have told doctors before when I had radiotherapy and previous scans that I have thyroid problem but have never been offered a thyroid guard

[humanbean in reply to Aquapuss]

I've never asked for a thyroid guard or shield myself - but then I haven't had any x-rays of any part of me from the chest up for many years. But I know some other people have and have been given one.

[TSH110 in reply to humanbean]

I asked for one at the dentist and they said they didn’t have one. I have refused point blank to have X-rays since. There’s nothing wrong with my teeth but two close relatives had a rare form of thyroid cancer so I don’t want to tempt fate because of greedy dentists wanting to maximise their profit. Don’t they teach them ALARP any more? Dental X-rays are quite low radiation, if my gob was hanging off it would be a different matter I would want to know what was wrong and would not object to an X-ray used as a diagnostic tool.

[Timetraveler67 in reply to humanbean]

Just wanted to mention they refused to give me a shield ( I’m in UK)

[Bellthyroid]

I had a CT scan and ended up having iodine-related thyroiditis which was really painful and I was unable to take my thyroid medication. My thyroid is still not back to normal 9 months later. My Endo was surprised they offered me a CT scan for gallbladder diagnosis and not ultrasound, he said he would never recommend a CT scan it not absolutely necessary as there are usually other options. Hope this helps as I wouldn't want anybody to go through the pain I have in the last 9 months.

[Aquapuss in reply to Bellthyroid]

That sounds awful, I hope you start to get better soon. So the CT scan was for your gall bladder? They usually do ultrasound to diagnose gall stones so that seems unusual. Are you able to take your thyroid meds now? Did it change your dose after getting thyroiditis? I have thyroiditis which comes and goes- was originally told it was de Quervain’s but it keeps coming back and haven’t had the CT scan ( for head injury) yet!

[Lynneypin]

Whenever I’ve asked for a thyroid shield they’ve said it would possibly interfere with the scan and they may have to do it twice... double the radiation.... so I opted for no shield 😕

[Localhero]

Sorry to know about your head injury.

I’ve no idea about the possible affects of radiation. However I just wanted to say that it sounds like you may have post concussion syndrome. I had this after a similar head injury a few years ago. I could not have imagined a bump to the head could have made me feel so ill for such a long time afterwards. I had all the symptoms you shared. Fatigue, brain fog, unable to use tech for very long... I also had the most awful anxiety. I had an MRI, also some time after the injury, which was clear.

The stuff I’ve read about concussion/post concussion syndrome suggests it resolves in a matter of weeks but that was not my experience. It took months. My GP tried to prescribe anti anxiety meds but I didn’t take them. The only thing that helped was rest. Oh, and trying to stay off my damned phone! My own theory is that thyroid issues made it more complex. I’ve no idea how or why. Just a personal hunch.

In any case I hope your scan is clear.

[tattybogle in reply to Localhero]

I agree.. my brother had a big bang on head and it took months to slowly stop having problems, but they did go. For about a year he couldn't handle going into a book shop because all the words on the shelves gave him an instant headache, and he couldn't concentrate to drive very far before getting headache either. In fact ... everything gave him a headache , and he got tired and angry much quicker than before , but he's alright now .

[Localhero in reply to tattybogle]

Oh gosh tattybogle So sorry to hear that about your brother. Before my head injury, I thought concussion was a mild thing, much less serious than a broken bone or the like. Now I know differently and really feel for others that have anything similar. I’d forgotten about the daily headache. OMG, that was so debilitating! Anyway, I’m glad your brother is better now. Hope he’s avoiding Derbyshire stone walls!

[Miffie]

My hypothyroidism is due to radiation therapy for a birth mark back in the early 1950s. It is well documented that the level of exposure at that time was nothing like as controlled as it now is. In addition my treatment went from the time I was about six months until I was at least five years old. Initially it was once every 4 -6 weeks, then 3 monthly, last two six months apart. Clearly well above average exposure and to a dose designed to be destructive. I have some memory of the treatment and a session took a bit of time. That form of treatment was withdrawn many years ago as the excessive exposure was found to have adversely affected many children.I have had many X-rays and a few CT scans since then but never requested a shield. I am not sure how much damage limited exposure at one event due to advancement in science could cause. If you are concerned then ask the hospital to supply a shield. I recommend contacting the department ahead of the appointment and advising them of your concerns. It may ensure they have a shield to hand. Given all the additional precautions due to the Covid situation they may not have everything to hand.

[TSH110 in reply to Miffie]

Omg that’s so awful. They used to X-ray therapy for ring worm (and a lot of other highly inappropriate things) - not a very good idea, with hindsight.

[Karenk13]

For a Head/ neck CT they wont give you a shield because it may partially block the scan . I had one 2 weeks ago as well as abdom one . They said if you were Hyper there was a chance the injectable dye would cause more problems but not so much for Hypo . Hope that helps 😊

[tattybogle in reply to Karenk13]

I've had Ct (Body ) with injectable dye (Iodine contrast i think) I'm Autoimmune hypo on Levo.. it didn't seem to have any effect on dose or blood results afterwards.

[besttimes]

I got concussion from a head injury during 2019 and felt really bad for quite some time afterwards. Keep up with the B complex and add extra B12.

[TSH110]

This study seems reassuring: ncbi.nlm.nih.gov/pmc/articl...

This one less so - it’s very detailed:

ncbi.nlm.nih.gov/pmc/articl...

[Xanthi]

I got told at my dentist that a shield could actually be worse as waves could get trapped and rebound, rather than going straight through; resulting in a higher dose.