The investigators have already proven that absolute total thyroidectomy gives elimination of anti-TPO antibodies. Our hypothesis is that this elimination also eliminates the typical Hashimoto symptoms, namely: Serious tiredness, increased need of sleep, pain in musculature and joints and dryness in eyes and mouth. The prerequisite for this effect is that the total thyroidectomy is meticulously performed. There exists no other treatment that can eliminate the antibodies. The study is randomized between operation and ordinary conservative medical treatment with thyroxine control and supplementation. The symptoms in both groups are evaluated by 5 different Quality of Life schemes, internationally approved.

The study hypothesis is that elimination of anti-TPO antibodies ameliorates the typical Hashimoto symptoms like tiredness,increased need of sleep, pain in musculature and joints and dryness in eyes and mouth. It is necessary that the total thyroidectomy is meticulously performed. We have proven the effect on the antibodies, and we have also proven that the operation procedure can be performed without more complications like recurrent nerve damage and hypocalcemia. Neutrality is secured by randomization done by a neutral institution, laryngoscopy by neutral doctors and instructions filling out the QoL-schemes performed by non-biased study nurses.

The study runs for at least 18 months with controls every 6 months. Blood samples are taken and international approved QoL-schemes are filled in. In addition to the randomised main group a side group of patients fulfilling 2 of the 3 inclusion criteria are followed in parallel in order to elucidate the spontaneous development of the disease and showing critical values of antibodies making the symptoms turn up.

Inclusion Criteria:

1. Patients referred due to typical symptoms, believed to be related to Hashimoto´s disease, but not relieved by thyroxin substitution. Optimal thyroid substitution treatment is already provided.
2. Anti-TPO>1000
3. Hypothyroidism with a need for thyroxin supplementation
4. Written informed consent by the patient - information particularly emphasising and quantifying the risk of complications (e.g. recurrent laryngeal nerve palsy). The patient should be informed by a medical endocrinologist as well as a surgeon.

Exclusion Criteria:

1. Patients <18 years of age.
2. Pregnancy.
3. Unable to comprehend information adequately to give informed consent.
4. General anaesthesiological contraindications.
5. An unexpected finding of cancer in the surgical group is not a reason for exclusion per se, but this group should be analyzed separately. It is expected that any different loading in Quality of life would bias the medically treated group.