4. Low oil supplies, although some people in the industry claim the price rises are solely due to security fears.
How will it affect us?
Well, many people are annoyed because, in addition to the rising price of oil, the British government was planning to put up fuel tax in September, which would make it even more expensive.
The government now says this plan is being looked at again.
In 2000, there were fuel tax protests. Drivers started panic-buying as the pumps started to run out.
People are concerned supplies will run short again.
What's being done to sort it out?
Opec has now decided to increase oil output by 2 million barrels a day from July and another 500,000 a day from August.
Oil prices have started to fall already.
Will oil run out?
There's only a limited supply of the stuff, but the main issue is the price.
As oil gets more expensive, countries will look to other forms of energy, such as wind or solar power.