Natural disasters
Many standard travel insurance policies exclude natural disasters and extreme weather conditions. Always check the T&Cs of your policy so you know exactly what you're covered for.
High-risk activities
Extreme sports and risky activities such as paragliding, skiing and scuba diving are normally excluded by standard travel insurance. It might be an idea to look into adventure travel insurance.
Any pre-existing conditions you haven't declared
You can normally still get travel insurance with medical conditions, but you need to declare them. You may have fewer options for cover, and the policy may be more expensive. But it's vital to have the right level of cover in case you need medical assistance.
Travelling against FCDO advice
Most travel insurance policies will exclude cover when you travel against government advice. So your cover is likely to be invalid if you travel to any of the areas of Pakistan the FCDO advises against.
Incidents involving alcohol and drugs
Pakistan is a dry country. Muslims aren't allowed to drink, but non-Muslim tourists may be able to have drinks in premises owned by hotels. But it's worth noting that incidents which occur while under the influence of drugs or alcohol are excluded by travel insurance policies.