Normally a symptom would be the visible or palpable effects of a disease. If you are infected with the measles virus, the infection - the fact that the virus is in your body - is the disease but the fever, the sickness, the red dots on your skin are the symptoms.
Side effects is normally used to describe unwanted effects of a medication. For example if you take medication to cure a headache, then the main effect - the wanted effect - is that is reduces the pain. Side effects can be that it makes you dizzy. In another medication - if it is against sleeplessness for example - making you dizzy is the wanted effect.
There are positive side effects to some medications. For example birth control pills might help to reduce acne. There are neutral side effects. For example if you take cortisone against an inflammation it can make you more active and make you get up at 6 o clock on sunday morning and wash your car. And there are negative side effects. Like if you take meds against anemia and you can get congestion.
Some medications have dangerous side effects.
Symptoms and side effects have one thing in common: they are different on different people. So if you are infected with a flu virus, and your entire family has the same virus, it might be that you have high fever for two days and are fine after that while your brother has moderate fever for two weeks. The same with medication. One person might have no side effects from a medicament, and another person gets them all.
Normally there is a frequency noted down with side effects in the meds insert... 1 in 10 people who took this medicament felt sick as a side effect, one in 100 people felt itching on their skin, 1 in 1000 people had an allergic reaction and 1 in 10000 people had a heart attack.
Symptoms, in terms or illness, are things that happen to you physically or mentally that hint about your condition. Symptoms of pregnancy can be, but aren't limited to: nausea, vomiting, dry skin, oily skin, dry hair, oily hair, strange cravings, can't stand certain smells.... Symptoms of the flu could be: Nausea, vomiting, fever, sweating, too hot, too cold, don't want to eat, dry/sore throat... You get the point. Hope I helped explain that.
side effect, soemthing that could happen if you say, take certain medication. its soething that COULD happen but soemthing that your not currently feeling or have symptoms of. symptomms are things that you are already showing...like if you were feeling sick or had a fever. side effecst become symptoms when you start showing them/feeling them
However, some people may have trouble being able to tell whether or not a symptom results from withdrawal or it is a side effect of the drug. Withdrawal symptoms and side effects are two separate sets of symptoms