Can I just take medicine and keep climbing?

No. Acetazolamide can help your body adjust, but it can also mask symptoms. If you need medication to continue, you are likely pushing your body beyond its current capacity.

Does being fit mean I won't get AMS?

Fitness level has no correlation with AMS. Even elite athletes get sick at high altitudes if they ascend too quickly.

Staying safe while trekking at high altitude

Acute Mountain Sickness (AMS) occurs when you ascend too quickly for your body to acclimatize to lower oxygen levels. Manage it by sticking to a strict 'climb high, sleep low' rule, staying hydrated, and descending immediately if symptoms worsen rather than improving.

Recognize the early signs. AMS feels exactly like a bad hangover. Watch for a throbbing headache, loss of appetite, nausea, and feeling unusually lethargic. If you have a headache that doesn't go away with ibuprofen, assume it is AMS.
Implement the 'climb high, sleep low' strategy. Never increase your sleeping elevation by more than 300 to 500 meters (roughly 1,000 to 1,600 feet) per day once you are above 3,000 meters. If you trek higher during the day, always return to a lower altitude to sleep.
Hydrate and avoid depressants. Drink at least 4 liters of water daily. Avoid alcohol, caffeine, and sleeping pills, as these depress your respiratory drive and make it harder for your body to get oxygen while you sleep.
Know when to descend. If you experience confusion, loss of coordination (stumbling like you are drunk), or have difficulty breathing while resting, descend at least 500 to 1,000 meters immediately. This is not optional; it is a life-saving necessity.

Can I just take medicine and keep climbing?: No. Acetazolamide can help your body adjust, but it can also mask symptoms. If you need medication to continue, you are likely pushing your body beyond its current capacity.
Does being fit mean I won't get AMS?: Fitness level has no correlation with AMS. Even elite athletes get sick at high altitudes if they ascend too quickly.