We all have trouble losing weight - to the degree we don't enjoy the process. But some people struggle more than others. Only you know for sure if your efforts are extreme - and if you are doing everything possible to lose weight - without success. This is one of the symptoms of a low thyroid condition, though it doesn't mean you have a thyroid condition! For that you'd need to be tested. Unfortunately most doctors don't test everything that needs testing, and you might be told you are "normal" when in fact you are not. In order for a proper assessment, the following blood tests must made:
Symptoms of a low thyroid can vary but a couple do stand out over the others: inexplicable weight gain and total exhaustion. The full list of symptoms is:
Heartburn
Constipation
Depression
Dry hair and hair loss
Dry skin
Fatigue
Greater sensitivity to cold
Slow heart rate
Swelling of the thyroid gland (goiter)
Peeling nails
Loss of outer third of eyebrows
Unexplained weight gain or difficulty losing weight
Carpal tunnel syndrome
Trouble focusing
Said this, there have been accounts of people losing weight with low thyroid, and these symptoms can be related to other issues so don't take every symptom as gospel. However, if you feel awful - find a doctor who will relentless make an effort to figure out what's wrong. Do not settle for being told your TSH is in range.