It "could" be a goiter, which is a swollen thyroid... We really can't make a determination from a photograph; the only way to know for sure is to visit your doctor and get an examination.
Do you have symptoms of a thyroid disorder?
Could be just muscular neck of the male
I think it's probably a good idea to get it checked out just for your own peace of mind, particularly since you have some symptoms that could indicate a thyroid condition.
I'd suggest you request a thyroid ultra sound, as well as a thyroid blood panel to include Free T3, Free T4, TSH and thyroid antibodies, Thyroid Peroxidase Antibodies (TPOab) and Thyroglobulin Antibodies (TgAb) to determine if you have Hashimoto's Thyroiditis. In addition, you should ask for Thyroid Stimulating Immunoglobulin (TSI), which is the definitive test to determine if you have Graves Disease...
Graves Disease is always associated with hyperthyroidism and while Hashimoto's is, typically, associated with hypothyroidism, it can be characterized in early stages with periods of hyperthyroidism.
Your symptoms of nervousness and feeling warm are often symptoms of hyperthyroidism, but would, typically, be accompanied by weight loss, diarrhea, hand tremors, heart palpitations, rapid heart rate, etc. Nervousness can also be a symptom of hypothyroidism, but would, typically, be accompanied by weight gain, constipation, dry, itchy skin, puffiness in the face, hands and feet, muscle soreness, etc. Both hyper and hypo are, typically, accompanied by fatigue.
If you can get the recommended blood tests done, you're welcome to post them here and we can help interpret them for you. Be sure to include reference ranges, as those vary lab to lab and have to come from your own report...
I forgot to mention that not everyone has the same symptoms with either hyper or hypothyroidism so don't be discouraged if you don't have any of the other symptoms I listed... that doesn't mean you don't have a thyroid condition...
Typically thyroid mass or swelling moves during swallowing; thyroid neck check can be more helpful in this case..
https://youtu.be/r_5dmUDlG9Y shws a case of multinodular thyroid
Thank you for your answers :) I have now an appointment at the doctor for tomorrow :) My neck now looks like this: http://img5.fotos-hochladen.net/thumbnail/hals2jlat3ew0o1_thumb.jpg So I am little worried but hopefully I will know more by tomorrow :)
It's good that you are getting it checked out... please let us know what the doctor has to say. Be sure to ask for the blood tests I specified above and be sure to get copies for your own records, then post them, with reference ranges when you get results
Take another picture with your head tilted back. The abnormal thyroid will stick out!