The Cyclomatic Complexity is measured by the number of (&&, ||) operators and (if, while, do, for, ?:, catch, switch, case, return, throw) statements in the body of a class plus one for each constructor, method (but not getter/setter), static initializer, or instance initializer in the class. The last return stament in method, if exists, is not taken into account.
Even when the Cyclomatic Complexity of a class is very high, this complexity might be well distributed among all methods. Nevertheless, most of the time, a very complex class is a class which breaks the Single Responsibility Principle and which should be re-factored to be split in several classes.