I saw this interesting video from Dr O the other day which shows some of the possible thyroid signs you can see on your fingernails. Check these out – jagged cuticles, selenium white lines and nails splits.
Obviously, these can come from other issues too, not least low stomach acid, but if you have them, it is worth doing at least the basal temperature test and then a full thyroid screen if your symptoms picture fits and the temperature test is positive.
See more on hypothyroid here in my Thyroid Problems factsheet, and here is the video for you: