I have recurrent hyperthyroidism as a result of Graves Disease. Overactive rather than underactive.
If there's a link between thyroid issues and autism it is likely to be the autoimmune part that is linked as Tuttle says. Graves, like Hashimoto's is an autoimmune disease.
Tuttle wrote:
How do you know that you are hypothyroid without being diagnosed?
Well, it could be a case of self-diagnosis which will lead to diagnosis. I self-diagnosed with hyperthyroidism 10 years ago after going to and from the the doctor with various symptoms for a while. I finally put them all together, came up with overactive thyroid, went back to the doctor and asked for a blood test. The doctor suppressed a laugh and humoured me by doing a blood test to "rule it out". The next day he called me at work and asked me to go in to see him immediately - turns out my thyroid levels were the highest he and the lab had ever seen .... Fortunately I was eventually able to get it under control with medication as I was desperate to avoid RAI or surgery. It was stubborn as hell though - took a long time. Now I'm stable without meds but every now and again it flares up and I have to start taking meds again.
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Female. Dx ASD in 2011 @ Age 38. Also Dx BPD