We are pleased to announce that on March 4, 2025, an updated Rich Text Editor will be introduced in the MyFitnessPal Community. To learn more about the upcoming changes, please click here. We look forward to sharing this new feature with you!
Synthroid Side effects

coburngirl2
Posts: 87 Member
Check with your doctor immediately if any of the following side effects occur while taking levothyroxine:
Less common
Chest pain or discomfort
decreased urine output
difficult or labored breathing
difficulty with swallowing
dilated neck veins
extreme fatigue
fainting
fast, slow, irregular, pounding, or racing heartbeat or pulse
fever
heat intolerance
hives or welts
increased blood pressure
increased pulse
irregular breathing
irritability
menstrual changes
nausea
pain or discomfort in the arms, jaw, back, or neck
shortness of breath
skin itching, rash, or redness
sweating
swelling of the eyes, face, lips, throat, or tongue
tightness in the chest
tremors
troubled breathing
Rare
Blurred or double vision
dizziness
eye pain
lack or slowing of normal growth in children
limp or walk favoring one leg
pain in the hip or knee
seizures
severe headache
Get emergency help immediately if any of the following symptoms of overdose occur while taking levothyroxine:
Symptoms of overdose
Change in consciousness
cold, clammy skin
confusion
disorientation
fast or weak pulse
lightheadedness
loss of consciousness
sudden headache
sudden loss of coordination
sudden slurring of speech
Some side effects of levothyroxine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common
Abdominal or stomach cramps
change in appetite
crying
diarrhea
false or unusual sense of well-being
fear
feeling not well or unhappy
feeling of discomfort
feeling of warmth
feeling things are not real
feelings of suspicion and distrust
hair loss
headache
increased appetite
mental depression
muscle weakness
nervousness
quick to react or overreact emotionally
rapidly changing moods
redness of the face, neck, arms, and occasionally, upper chest
restlessness
trouble getting pregnant
trouble sitting still
unusual tiredness or weakness
vomiting
weight gain
weight loss
Less common
Chest pain or discomfort
decreased urine output
difficult or labored breathing
difficulty with swallowing
dilated neck veins
extreme fatigue
fainting
fast, slow, irregular, pounding, or racing heartbeat or pulse
fever
heat intolerance
hives or welts
increased blood pressure
increased pulse
irregular breathing
irritability
menstrual changes
nausea
pain or discomfort in the arms, jaw, back, or neck
shortness of breath
skin itching, rash, or redness
sweating
swelling of the eyes, face, lips, throat, or tongue
tightness in the chest
tremors
troubled breathing
Rare
Blurred or double vision
dizziness
eye pain
lack or slowing of normal growth in children
limp or walk favoring one leg
pain in the hip or knee
seizures
severe headache
Get emergency help immediately if any of the following symptoms of overdose occur while taking levothyroxine:
Symptoms of overdose
Change in consciousness
cold, clammy skin
confusion
disorientation
fast or weak pulse
lightheadedness
loss of consciousness
sudden headache
sudden loss of coordination
sudden slurring of speech
Some side effects of levothyroxine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common
Abdominal or stomach cramps
change in appetite
crying
diarrhea
false or unusual sense of well-being
fear
feeling not well or unhappy
feeling of discomfort
feeling of warmth
feeling things are not real
feelings of suspicion and distrust
hair loss
headache
increased appetite
mental depression
muscle weakness
nervousness
quick to react or overreact emotionally
rapidly changing moods
redness of the face, neck, arms, and occasionally, upper chest
restlessness
trouble getting pregnant
trouble sitting still
unusual tiredness or weakness
vomiting
weight gain
weight loss
0
Replies
-
pretty yes to all of the above at some point or another0
-
Reading through the list I agree have had most of them at some point. however the whole body acy and back pain has been a constant.0
-
I would definitely have your dr try and help you address that, because there are some things we just shouldn't have to get used to0
-
I have spoken with my endo but he is only concerned with getting my tsh numbers down after my last appt. I am changing my primary hoping this makes a difference0
-
Have they done a whole body scan on you recently? The only reason the numbers should be up is if the Synthroid isn't at the right dosing/being absorbed or if there is a recurrence. My TSH has been "undetectable" so definitely he needs to be doing something for you. I've never had luck with male drs other than my surgeon. He has been awesome. All male drs have ever told me is "you need to lose weight." Really? I had NO idea :grumble:0
-
No scan he gave me a script for an u/s which I have to schedule. I did gain weight and he thinks that is why the number s went up. I asked him about the t3 converting and he said he found no evidence to support that as a reason......I am thinking maybe if I lost some weight I can lower the dose... I am going for a new round of blood work next week and another apt after that to see if anything changed.0
-
Are you in the US? I only ask because the way my doctors act, I sorta thought it was standard to do the whole body scan? Hopefully you and he can get on the same page so you can start feeling better0
This discussion has been closed.