My doctor reduced my euthyrox 100 to 50 since that time I feel tired and I have fast heart beats, he said I have under active thyroid with nodules?

Underactive thyroid. It should be easy to check whether you're getting enough thyroid hormone. Have your doctor (if s/he hasn't already) order a TSH test. If the TSH test is high, you need more thyroid hormone. The nodules usually do not have any effect on thyroid hormone levels (with the single exception of a toxic nodule, which makes your thyroid overactive).
Thyroid medication. Changes take time...Talk to your physician.

Related Questions

Pregnant heard heart beat at 7 wk 4 days. Got blood work and TSH came at 6.26. Doc called in levothyroxine. Will my baby ok or possible miscarriage?

Should be ok. It is important for best outcomes to keep your TSH less than 2.5. This is why your doctor put you on synthroid (thyroxine). He/she will most likely check the TSH level again in 4-6 weeks. Read more...

Dear doctor, can u please suggest me remedy for post effect of red eyes, fast heart beat and light swelling for some time after I drink beer or whisky b?

Allergic reaction. Benadryl (diphenhydramine) is great for allergic reactions but when mixed with alcohol would be very sedating. The simply solution is to avoid alcohol for now and see an allergist who can determine what you are actually allergic to. They may be able to treat you for that allergy and you should have no more issues. Continued consumption of alcohol could lead to worsening reactions. Read more...
Alcohol Allergy. It sure sounds like you are allergic to alcohol and should consider not drinking. Read more...