Excessive levels of acetylcholine, while essential for normal brain and nervous system function, can lead to adverse effects. This condition is known as cholinergic excess or cholinergic toxicity. Here's an explanation of why excessive acetylcholine can be problematic:

1. Overstimulation of Nervous System: Acetylcholine is a neurotransmitter that transmits signals between nerve cells and muscle cells. When there's an excess of acetylcholine, it can lead to overstimulation of nerve cells. This can result in symptoms such as anxiety, restlessness, muscle twitching, and tremors.

2. Muscle Weakness: While acetylcholine is necessary for muscle contraction, too much of it can lead to muscle weakness and fatigue. This can manifest as muscle cramps, difficulty coordinating movements, and even paralysis in extreme cases.

3. Gastrointestinal Distress: Excess acetylcholine can stimulate the digestive tract excessively, leading to symptoms like nausea, vomiting, diarrhea, and abdominal cramps.

4. Excessive Salivation and Sweating: Overstimulation of salivary glands and sweat glands can result in excessive salivation (drooling) and profuse sweating.

5. Cognitive Disturbances: Cholinergic excess can also affect cognitive function. It may lead to confusion, memory problems, hallucinations, and difficulty concentrating.

6. Cardiovascular Effects: In rare cases, excessive acetylcholine can affect heart rate and blood pressure, potentially leading to bradycardia (slow heart rate) and hypotension (low blood pressure).

Cholinergic excess can occur due to various reasons, including the use of medications or supplements that increase acetylcholine levels, poisoning with cholinesterase inhibitors, or certain medical conditions. It's crucial to be cautious when using supplements or medications that affect acetylcholine, especially if you're taking multiple substances with similar effects. Always follow recommended dosages and consult with a healthcare professional if you experience symptoms of cholinergic excess.